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The Cuprate Ln2CuO4 (Ln: Rare Earth): Synthesis, Crystallography, and Applications

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Basma Marzougui, Amira Marzouki, Youssef Ben Smida and Riadh Marzouki

Submitted: 02 October 2022 Reviewed: 28 November 2022 Published: 04 January 2023

DOI: 10.5772/intechopen.109193

Crystal Growth and Chirality IntechOpen
Crystal Growth and Chirality Technologies and Applications Edited by Riadh Marzouki

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Crystal Growth and Chirality - Technologies and Applications

Edited by Riadh Marzouki and Takashiro Akitsu

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Abstract

This chapter is concerned with a study of undoped and doped cuprates of the general formula Ln2CuO4 (Ln = rare-earth metal) and Ln2–xMxCuO4±δ (Ln = rare earth and M = Sr, Ba, Ca, Ln’, Bi, and 3d metal). The crystal structures of the undoped and doped cuprates having the notations (T, T′, T*, S, and O), significantly depend, however, on the synthetic route. The topotactic synthesis is a specific method, which allows the transformation of the cuprate from the T to T′ structure. The importance of these materials originates from the discovery of the unconventional superconductors of the Ce-doped Ln2CuO4. The cuprate materials could function as insulators or semiconductors which are valuable tools in optoelectronic applications. The doped cuprate materials are good ionic conductors and are found useful as electrodes in fuel cell applications. The undoped cuprates reveal high dielectric properties.

Keywords

  • cuprate
  • synthesis
  • crystal structure
  • superconductivity
  • ionic conductivity
  • optical properties

1. Introduction

Perovskite with the general formula ABO3 is an important structure in solid-state chemistry which has been applied in many fields. From the ABO3 structure, several approximate structures can be derived, which are equally important and reveal excellent physical and chemical properties. Historically, Perovskite was first depicted by geologist Gustav Rose in 1830 as a particular mineral CaTiO3 calcium titanate [1]. Today, ‘Perovskite’ refers to a group of compounds with the same crystal structure and similar unit cell parameters. The partial and total substitution of the cationic atoms of the stochiometric ABO3 allows to obtain several structures with attractive physical and chemical properties [2]. Figure 1 shows the phases obtained after the modification of the central compound ABO3.

Figure 1.

Derivatives reached from the central structure perovskite ABO3.

Horizontally, the diagram shows that phases of layered structure can be formed by the interlacing of motifs (AO) or (BO2) and motifs (ABO3). Vertically, it shows the intermediate phases that can be obtained by varying the oxygen content through the oxidation/reduction process [3, 4].

The Ruddlesden–Popper phases (RP), of the general formula An+1BnO3n+1, have a structure derived from perovskite, which can be described as the stacking of n successive perovskite layers (ABO3) alternating with one sheet (AO) of NaCl structure along axis c [5].

Like the perovskites, the RP phases show high structural flexibility and more particularly the cuprates of the general formula ACumOn. They are copper-based oxides alloyed with other elements, with different coordination numbers for Cu and consequently different geometry of CuO2 polyhedra. They may be a chemical compound in which copper forms an anion or complex with an overall negative charge [4].

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2. The discovery of the superconductivity of cuprate

Although the undoped cuprates are considered electrical insulators, the “doped” cuprates are regarded as unconventional superconductors [6]. Site A may be rare earth or shared by other rare earth (Sc, Y, and the lanthanides elements) or alkaline earth of different valences (Be, Mg, Sr, Ca, Ba) [7, 8, 9, 10, 11, 12]. This gives these materials’ different physical properties in relation to the substitution coefficient. These compounds have all different structures but have in common the “active” CuO2 plans in which the superconductivity is formed [13].

The first cuprate superconductor was discovered in 1986 in lanthanum barium copper oxide by the scientists Georg Bednorz and Karl Alexander Müller [14]. The critical temperature for this material was 35K, much higher than the previous record of 23K [15]. This discovery resulted in a significant increase in research on cuprates, which resulted in hundreds of publications between 1986 and 2001. Bednorz and Müller received the Nobel Prize in Physics in 1987 [16], just one year after their discovery.

Superconductivity in cuprates is considered non-conventional and is not explained by BCS theory (Bardeen-Cooper-Schrieffer) [17]. The potential pairing mechanisms for cuprates superconductivity continue to be the subject of extensive discussion and research. In 1987, Philip Anderson proposed that super exchange could be used as a mechanism for coupling high-temperature superconductors [18]. In 2016, Chinese physicists observed a correlation between a cuprates’ critical temperature and the size of the charge transfer gap in that cuprate, offering an explication for the super exchange hypothesis (the strong antiferromagnetic coupling between two neighbor cations through a non-magnetic anion) [19].

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3. Crystal structure and synthesis of cuprate

The two typical structural types of Ln2CuO4 double oxides are assigned by T (or O) and T′ [16]. The indicative T′ means that the symmetry of the structure is tetragonal while the prefix O designates that the symmetry is orthorhombic. A third structural type exists and is designated by T* for certain oxides of the general formula Ln2–y-xLn′yMxCuO4 (where Ln and Ln′ are lanthanides and M an alkali or alkaline earth such as Ba or Sr) [20, 21, 22]. The rare-earth ionic radius of the Ln2CuO4 oxides (Ln = lanthanides) is an essential criterion that imposes the type of structure adopted. All Ln2CuO4 compounds stabilize in the T′-type structure at room temperature, except for Ln=La which adopts the T-type structure. This difference is due to the enormous size of the La3+ ion which prevents the stabilization of the T′ structure. However, the small ionic radii of the other lanthanides favor the crystallization of the T′ phase, the common prototype for this phase of which is the compound Nd2CuO4 [23].

3.1 T-type structure (La2MO4 system with M = Cu, Ni, and Co)

The T-type structure relates to the La2MO4 system where M = Cu, Ni, and Co. At elevated temperatures, the La2MO4-type compounds correspond to the K2NiF4-type structure of tetragonal symmetry with the space group I4/mmm [24, 25, 26]. The structure is described by the stacking, along the c-axis, of sheets of the MO2 type separated from each other by double layers of the NaCl type or, by the stacking of the layers of octahedron MO6 of the perovskite-type which are translated relative to each other by (½, ½, and ½) and separated by La-O sheets of the NaCl type [27] (Figure 2).

Figure 2.

Unit cell of the T-type structure: (a) HTT quadratic phase (Space Group: I4/mmm) (ICSD 41643), (b) LTO Low-temperature orthorhombic phase (Space Group: Bmab) (ICSD50265).

The coordination of the lanthanum atom is equal to 9 or 4 + 4 + 1 oxygen ions with different bond lengths. The shortest bond (strong bond) is between the apical oxygen and the rare-earth atom (Ln–O)+. The transition metal is in coordination 4 (four) with respect to the equatorial oxygen and 2 with respect to the apical oxygen. The lengths of Map bonds vary according to the type of transition metal M [28]. Indeed, the Co–Oap and Ni–Oap bonds are equivalent, while the length of the Cu–Oap bond is lengthened on the c-axis by the Jahn Teller effect [29] due to the volume state of the Cu2+. It is equal to 13.15 Å for La2CuO4 while it is between 12.55 Å and 12.70 Å for La2CoO4 [30] and La2NiO4 [31]. The octahedra MO6 is perfectly aligned with the c–axis; in case, HTT (high-temperature tetragonal) is ideal. At room temperature, the phases of the three systems: La2CoO4, La2NiO4, and La2NiO4, have an orthorhombic structure of the Bmab type called “low temperature orthorhombic” (LTO).

3.2 T′-type structure

The structure of the T′ type derives from that of the T type which results from a displacement of the apical oxygen atoms in the tetrahedral sites formed by the lanthanide ions, from where the layers of the NaCl type are replaced by layers of the fluorite type. The coordination number of Cu becomes 4 (square plane coordination) and that of Ln is 8 instead of 9 [32, 33]. This structural transformation leads exclusively to a change in the coordination of the oxide; thus, the cation M is in square plane coordination, and the LnO2 layers are of the fluorine type and no longer of the NaCl type. Therefore, the crystal structure of the T’ phase can be described as an entanglement of fluorite (Ln/O2/Ln) blocks with infinite shell blocks CuO2. However, the space group remains the same for the 2 structures. The structures of Nd2CuO4 [12] and Pr2CuO4 [34] are shown in Figure 3. The atomic positions of the two structures T and T’ are presented in Table 1. The values of the atomic coordinates have been obtained from the crystallographic information file (CIF) obtained from the ICSD database.

Figure 3.

Structure of the typical quadratic phase T’ (ICSD 261660).

T structureT’ structure
AtomSiteCoordinatesAtomSiteCoordinates
Ln4e(0, 0, z) z ≈ 0,35Ln4e(0, 0, z) z ≈ 0,35
Cu2a(0, 0, 0)Cu2a(0, 0, 0)
Oeq4c(0, 1/2, 0)O14c(0, 1/2, 0)
Oap4e(0, 0, z) z ≈ 0,18O24d(0, 1/2/, 1/4)

Table 1.

Atomic positions of the T and T’ structures with the space group I4/mmm.

3.3 T* type structure

The structure of the T* type consists of a stack of pyramids’ layers (CuO5) separated either by layers (LnO) of the NaCl type, or by layers of the fluorite type (Figure 4). As a result, this structure is intermediate between those of the T and T′ types. The stacking sequence of the atomic planes along the c-axis is A│B│A│C│A, with A: CuO2, B: Ln–O2–Ln, and C: LnO–LnO. The Cu2+ cation is surrounded by five oxygen atoms, thus, forming a square-based pyramid while the Ln3+ cations are distributed in the coordination sites 9 and 8 in an ordered manner [22]. The structure of the T* type phase is obtained by following a thermodynamic competition between the factors, e.g., chemical composition and pressure influencing the stability of the T and T′ phases. Due to this competition, the existence of this phase is extremely limited and coincides with the following values of the tolerance factor: 0.85 ≤ t ≤ 0.86 [31]. The existence and presence of two ions Ln3+ and Ln’3+ of varied sizes cause the crystallization of the oxide of type (Ln, Ln′)2CuO4 in the T* type structure. This is the case where Ln is La3+ and Ln′ is less voluminous ion such as Sm3+, Eu3+ , Gd3+ , Dy3+, and Tb3+ . The domain of the T*-type phase existence can be increased by the presence of a divalent cation with a large ionic radius such as Sr2+ which usually occupies the coordination site 9 [32]. Thus, the structure of the T* phase can include several oxides such as (La, Ln, Sr)2CuO4 and (La, Ln′)2CuO4 (Ln = Sm, Eu, Gd, or Tb, and Ln′ = Dy, Tb, or Nd) [30]. The structure of the T* type phase has also a quadratic symmetry, and the space group of Nd2–x–yCexSryCuO4- δ is P4/nmm [35] for example.

Figure 4.

Projection of the crystal structure of (Nd1.32Sr0.41Ce0.27)CuO3.93 (ICSD 65871) which belongs to the T* structure type.

3.4 S-Type structure

The S-type structure [36] is a model used mainly to describe oxygen-deficient compounds such as Ln2CuO4–x (Ln = Pr, Nd, Sm, Eu, Gd) [37]. Unlike T, T’, and T*, the S phase has oxygen vacancies at the equatorial sites, half of which are occupied. The oxygen vacancies are ordered such that Cu adopts a square planar coordination as shown in Figure 5. The copper atoms are surrounded by 2Oap and 2Oeq instead of 4Oeq in the T’ phase. This is a major difference between the two phases S and T’ since the arrangement of CuO4 square planes in the S-type structure does not form 2D layers, but 1D chains which share the following corners and orientations [38, 39]. The S-type phase has orthorhombic symmetry with a space group Immm [39].

Figure 5.

Projection of the crystal structure of SrCuO3 which belongs to the S structure type (ICSD 15127).

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4. Effect of doping in phase transition of cuprates

The nature of the Cu–O bond in cuprates is strongly related to doping. Various configurations are found. For example, for the La2–xSrxCuO4 system [40, 41], the structure is of the K2NiF4 type (T phase). It contains CuO6 octahedra arranged in a planar row.

While the Nd2–xCexCuO4 [42] system exhibits a structure similar to Nd2CuO4 type (T’ phase) in which the apical oxygens in the T phase structure are shifted away from the Cu atoms in order to form lines of oxygen atoms along the c-axis perpendicular to the CuO2 planes. In the Sr2CuO3 phase (S phase), the CuO3 chains, running along the a-axis of the orthorhombic structure, were isolated [43]. The T, T′, and S structures are shown in Figure 6. Due to the elimination of half of the oxygen atoms noticed in the CuO2 planes, the structure is transformed from the T phase to the S phase. The translation of the apical oxygens in the face positions of the lattice transforms the structure of the T phase to T’ phase. The transformation between the phases T, T′, and S is observed in the Nd2CuO4 -Sr2CuO4 system [41]. Indeed, heating T-type phases such as La2CuO4, La2NiO4, and La2CoO4 under various oxygen pressures lead to the formation of oxygen-rich phases, with biphasic regions between these phases and the stoichiometric compounds La2MO4 (M: Cu, Ni, Co) [42]. In the case of La2CuO4, the obtained sample is La2CuO4.08 and La2CuO4.03 [44, 45].

Figure 6.

Structures of (a) T-La2CuO4, (b) T′-Nd2CuO4, and (c) S-Sr2CuO3.

The oxygen-rich phase shows superconductivity below 40 K. The reduction of Ln2CuO4 compounds (Ln: La, Pr, Nd, Sm, Eu, Gd) using hydrogen at low temperature [10] leads to the formation of new Ln2CuO4–δ compounds, with δ = 1/3 for Ln = La and δ = ½ for Ln = Pr, Nd, Sm, Eu, and Gd. For the compounds with La, Pr, and Nd, they exhibit structures similar to Sr2CuO3 [46, 47, 48].

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5. The influence of hole doping on the antiferromagnetic order of CuO2 planes

Doping is the operation that modifies the concentration of charge carriers in the CuO2 planes. There are two ways of doping the compound either by substituting a cation with another of different valences, for example, in the La2–xSrxCuO4 system, the La3+ is substituted by Sr2+ [49], or simply by adding oxygen. In the undoped compounds, the planes adjacent to the CuO2 planes consist of trivalent cations X3+ (La3+ in the phase La2CuO4 or Bi3+ for Bi2Sr2CaCu2O8). Only two of the three electrons provided by X3+ are needed for bonding X3+-O2−. The electron remaining is transferred to blueprints Cu2+(O2–)2. The unit cell CuO2 takes an electron from the two neighboring layers XO, thus, ensuring electronic neutrality. However, when a divalent Z2+ ion is partially substituted for the trivalent X3+ ion, an electron deficit is created in the CuO2 planes [50]. This process can also be described as introducing holes in the copper-oxygen planes. These holes transform the 3d9 states of Cu2+ into Cu3+ (S = 0), and these ions represent a Cu2+ (S = ½) bonding state with a hole residing mainly in the four neighboring 2p orbitals of the oxygens that is called a “Zhang-Rice” singlet [51]. The introduction of hole-like charge carriers significantly alters the long-range antiferromagnetic ordering of the system as shown in Figure 7.

Figure 7.

Schematic representation of the influence of hole doping on the antiferromagnetic order of CuO2 planes [52].

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6. Electric properties of cuprate

Undoped Ln2CuO4 cuprates are weak electrical conductors [53] because they have neither free electrons nor anionic vacancy. This low conductivity is due to the presence of two oxidation states of copper Cu2+ and Cu+. However, doping gives rise to defects or free electrons which allow electrical conduction.

An electrical conductor allows the passage of electrical current and indicates that in this solid, there are structural defects and/or conduction electrons. For La2–x(Ba,Sr)xCuO4±δ, each electron with a valence of 6s of Ba or 5s of Sr interacts with 2p of oxygen [54]. This interaction corresponds to the energy that participates in the formation of the solid. This energy associated with the interaction stabilizes the valence electron and prevents it from participating in electrical conductivity, which makes the material insulating. It is, therefore, necessary for the valence electrons to be able to participate in electrical conductivity so that they are freed from their bond of valence.

When the electrical current is established, a part of the electrical energy is still distributed over all the ordered atoms, barely modifying the different movements of the electrons, which can no longer leave their atom except in the absence of a defect. On the other hand, for atoms in a defect position, their conduction electron no longer has a synchronous movement with the others, and they can more easily receive electrical energy. As a result, when the electrical current is established, the conduction electrons of the atoms in the defect position can gradually leave their atom, which allows the disturbances generated by the connections to propagate [55]. It is the electrical energy that allows them to cross the gap, which without it, it retains in their corresponding atom. It is appropriate to call such defects with conductors to distinguish them from other resistant structural defects. This is a situation reminiscent of the semiconductor state, the difference coming from the number of defects, and more numerous carriers in a metal or a metallic oxide. Metal is a conductor in which conduction electrons are excited by energy electric.

The mechanism of conductivity in cuprates considers the conductive solid as a mixture of two phases: one ordered and the other disordered. If in the disordered phase, there are too many resisting defects close to the paths of the electrons, then the body is conductive, semi-conductive, or insulating at any temperature [56]. If the number of resistant defects is sufficiently low, the body is superconducting. The notion of resistant defects has the advantage of making it possible to understand the significant difference between oxides and metals. The 2p holes on the oxygen atoms are resistant defects. Due to the importance of electrical properties for this family of materials, they are used in several areas of electricity and energy storage such as solid-oxide fuel cells and capacitors. Indeed, cuprates are used as cathodes for fuel cells. These cathodes must be good electrical and ionic conductors, stable in an oxidizing medium, and compatible with the electrolyte and interconnector materials. The most encountered materials are of the A1−xSrxBO3 type, such as manganite and lanthanum cobaltite doped with strontium La0.6Sr0.4MnO3 (LSM) [57] and La0.7Sr0.3CoO3−δ (LSC) [58]. Recently, new materials of general formula A2MO4+δ with RP structure have been studied and show promising results.

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7. Dielectric properties

Doped Ln2CuO4 lanthanide cuprates are also characterized by their high dielectric properties due to the high value of the dielectric constant ε′ (ε′ > 104) and the low dielectric loss [59, 60]. The La2CuO4 oxide has a dielectric constant ε′ in the range 103–104 [61]. The dielectric constant of La1.95 Sr0.05CuO4±δ is about 2 × 105 much larger than that of La2CuO4 [11]. The increase in this constant was explained by the increase in the concentration of holes in the material [62]. For the cuprate Eu2CuO4, the dielectric constant was about 103–104 in the frequency range between 1 kHz and 1 MHz for the temperature range from 173 K to 423 K [63].

Indeed, at the microscopic scale, the dielectric permittivity of the material is linked to the electrical polarizability of the molecules or atoms constituting the material. Dielectric materials are polarized in an applied electric field [64]. A certain amount of time is required to orient the dielectric dipoles depending on the direction of the applied electric field. This period is called “relaxation time,” which can be attributed to an inhomogeneous microstructure consisting of cuprate grains, separated by insulating grain boundaries.

The dielectric losses encountered in most materials, in particular noticed for cuprate, originate directly from polarization due to orientation because its range of variation can be located between 102 and 105 Hz [65]. This behavior can be explained in terms that at low frequency, there is a phase shift between the polarization vector and the electric field [64]. But at sufficiently high frequencies, the duration of the electric field is reduced compared to the relaxation time of the permanent dipoles. Thus, the orientation of the latter is no longer influenced by the electric field and remains random. We also observe that the dielectric loss decreases when the temperature increases because the conduction in the dielectric ceases and is believed to be a negligible phenomenon.

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8. Optical properties of cuprate

Cuprates represent a very interesting class of semiconductor and superconductor materials, widely known for their important technological applications in the field of display devices, optical smart windows, electrochromic devices (ECDs), and gas sensors [66, 67]. These materials of which optical properties vary with the reduction and/or the oxidation by the injection of ions and electrons which modify their electronic structure are responsible for the change of its visual qualities.

So far, most of the research on Ln2CuO4 and Ln2–xMxCuO4 (Ln = lanthanides, M = Ca2+, Sr2+, and Ba2+) have focused on superconductivity, but few studies in the literature on the preparation and optical properties of Ln2CuO4 and Ln2–xMxCuO4 materials in the UV–VIS–NIR region are reported [68]. Doped and undoped Ln2CuO4 can be used as photocathodes for the photo-electrochemical decomposition of water, in which the Cu2+ ion provides the small bandgap of this material while the incorporated lanthanum ion provides the energy-level adjustment [69]. According to several studies [46], the La2CuO4 electrode acts as a photocathode for the photo-electrochemical decomposition of water and presents a photo-current of 0.5 mA/cm2. For effective photocatalysts, the bandgap must be large enough to support the 1.23 eV dissociation energy of water. On the other hand, the bandgap should be less than 2.1 eV [70], which would allow the materials to capture and absorb most of the solar energy. For example, La2CuO4 shows broad absorption in the UV–visible region [200–800 nm] with an energy band of about 1.24 eV [71, 72] attributed to O2– → Cu2+ charge transfer. For Ln2CuO4 (Ln=Pr, Nd, Sm, and Gd), the gap energy is 0.79 eV; 1.06 eV; 1.20 eV, and 1.36 eV, respectively [73]. Chyi-Ching et al. [74] related the observed optical bandgap to the rare-earth ionic radius and show that the bandgap decreases with increasing ionic radii. The optical properties of lanthanum copper oxide-doped La2–xMxCuO4–δ (M = Ca, Sr, and Ba) have been the subject of some articles [71, 75, 76]. They consider the effect of the grain size on the optical properties of the prepared samples. Therefore, they used soft chemical synthesis methods, such as sol–gel, combustion and co-precipitation [10, 11, 77]. We can see that the optical bandgap decreases with increasing Ca2+ and Ba2+ levels but evolves in the same direction in the case of Sr2+ and undoped La2CuO4, which was 1.88 eV [78]. This value is different from the value quoted by other authors [79].

Throughout the UV–VIS–NIR region, the La2–xCaxCuO4 cuprates have a wide absorption band and a bandgap that increases linearly with the doping level at 0 ≤ x ≤ 0.12; which will respond effectively to its use as a photocatalyst [62, 69].

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9. Topotactic reduction of cuprates

Ln2CuO4 compounds (Ln = lanthanide) can also be reduced to lead to Ln2CuO4–δ oxygen-deficient phases. Topochemical deintercalation of O2− ions from transition metal oxides can be used to prepare a large number of metastable phases that contain coordination geometries and transition metal centers in unusual oxidation states [80]. The Ln2CuO4–δ oxygen-deficient phases obtained after reduction constitute an obligatory intermediate step for the transformation of the T to T’ phase [81].

The reduction reaction of a transition metal oxide is normally conducted by artificially reducing the partial pressure of oxygen in the system, either by pumping oxygen or purging with an inert atmosphere (stream of H2 gas) or by the use of highly electropositive binary metal hydrides (LiH, NaH, MgH2, CaH2, SrH2, and BaH2) in a vacuum tube.

The importance of the T’ phase is due to the superconductivity properties of the cuprates. Therefore, numerous attempts have investigated the possibility of transforming the T phase into the T′ phase [10, 80, 81, 82] use of a topotactic transformation. For cuprates, e.g., topotactic transformation can be performed in two steps: reduction using hydrides of electropositive metals such as NaH, LiH, and CaH2 or using H2. The reduction step creates it possible to find an intermediate phase that is transformed by oxidation to the required structure. For example, using CaH2, La1.8Nd0.2CuO3.5 is synthesized from La1.8Nd0.2CuO4 [10]. T′-(La-Ln)2CuO4 phase was first synthesized by Tsukada et al. [83] at a low temperature of 600°C. In this context, researchers are chasing stability conditions to realize whether T′-La2CuO4 phase exists only as a thin layer. Thus, using the co-precipitation method, Takayama Muromachi et al. [84] stabilize T′-La1.8Y0.2CuO4 phase at low temperature (600°C).

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10. Synthesis of new Ln2CuO3.5 compounds by reduction with CaH2

New compounds were synthesized using hydrogen reduction as a synthetic method to obtain compounds of the Ln2CuO3.5 (Ln: Pr, Nd, Sm, Eu, Gd) [23, 79, 85] and La2CuO3.67 type [78]. These interesting phases are obtained by heating the compounds of the Ln2CuO4 mother phases under a reducing atmosphere of the order of 5% moles of H2/He at a moderate temperature of 300°C. After inspection with X-ray diffraction, the structures obtained for La, Pr, and Nd are all similar to those of the Sr2CuO3 [86], whereas those of the compounds containing Sm, Eu, and Gd are different. The oxidation of the compound La2CuO3.67 in the temperature range of 300–500°C leads to a new La2CuO4+δ system of the T′ type similar to the structure of Nd2CuO4 [82]. The oxygen excess is exceptionally high, ranging from 4.10 to 4.42. Annealing beyond 620°C in the presence of atmospheric oxygen transforms the structure back to the original structure of the K2NiF4 (T phase) type, although the excess oxygen varies up to 4.06 and with a small orthorhombicity compared with the starting product La2CuO4. The oxidation of the other S-Ln2CuO3.5 phases (Ln: Pr, Nd, Sm, Eu, and Gd) above 300°C leads to the original T′ structure, but the excess oxygen varies between 3.98 for the compounds (Eu, Gd) and 4.03 for the compound Nd [39, 87].

There is a notable change in the lattice parameters between the S, T′, and T phases. For La2CuOx, the transition from the T structure to the S structure leads to the elongation of the a- and b-axes and to compression of the c-axis, with respect to the structure T. Consequently, a large increase in the volume of the unit cell (~6%) is observed [88, 89]. The decrease in the c-axis was associated with the loss of oxygen in the CuO2 plane, as in the example of La2–xSrxCuO4–y. The transformation of the T′-La2CuO4+δ phase to the T phase produces a big decrease of about 4.3% in the unit cell volume.

11. Conclusion

In this chapter, we have described the most common structures of the cuprate materials, and the chemical reaction used to obtain it, especially the topotactic reaction. The cuprate materials with the general formula Ln2CuO4 were used particularly in the superconductivity field, but later, the materials have been successfully used in other applications as semiconductors or as anionic conductors, respectively. Thus, the cuprate of the formula Ln2CuO4 could be applied in photolysis, photoluminescence, fuel cells, and as dielectric materials.

Acknowledgements

The authors thank the Tunisian Ministry of Higher Education and Scientific Research for the funding of this work within the framework of the laboratory program contract (LR16CNRSM02). The authors extend their appreciation to the Deanship of Scientific Research at King Khalid University, Saudi Arabia.

Abbreviation

ICSDInorganic Crystal Structure Data Base

References

  1. 1. Katz EA. Perovskite: Name puzzle and German-Russian odyssey of discovery. Helvetica Chimica Acta. 2020;103:e2000061
  2. 2. Kim H-S, Lee C-R, Im J-H, Lee K-B, Moehl T, Marchioro A, et al. Lead iodide perovskite sensitized all-solid-state submicron thin film mesoscopic solar cell with efficiency exceeding 9%. Scientific Reports. 2012;2:1-7
  3. 3. Kharton V, Marques F, Atkinson A. Transport properties of solid oxide electrolyte ceramics: a brief review. Solid State Ionics. 2004;174:135-149
  4. 4. Colville A, Geller S. The crystal structure of brownmillerite, Ca2FeAlO5. Acta Crystallographica, Section B: Structural Crystallography and Crystal Chemistry. 1971;27:2311-2315
  5. 5. Beznosikov B, Aleksandrov K. Perovskite-like crystals of the Ruddlesden-Popper series. Crystallography Reports. 2000;45:792-798
  6. 6. Belich N, Udalova N, Semenova A, Petrov A, Fateev S, Tarasov A, et al. Perovskite puzzle for revolutionary functional materials. Frontiers in Chemistry. 2020;8:550625
  7. 7. Özdemir ZG, Kılıç M, Karabul Y, Mısırlıoğlu BS, Çataltepe ÖA, İçelli O. Temperature dependence of dielectric properties and electrical conductivity of EuBa2Ca2Cu3O9-x. In: WITAM-2016. 2016. p. 156. DOI: 10.1016/j.mssp.2017.02.020
  8. 8. Khandale A, Pahune B, Bhoga S, Kumar R, Tomov R. Development of Pr2-xSrxCuO4±δ mixed ion-electron conducting system as cathode for intermediate temperature solid oxide fuel cell. International Journal of Hydrogen Energy. 2019;44:15417-15435
  9. 9. Chaudhari V, Khandale A, Bhoga S. Sr-doped Sm2CuO4 cathode for intermediate temperature solid oxide fuel cells. Solid State Ionics. 2014;268:140-149
  10. 10. Marzougui B, Houchati MI, Smida YB, Chniba-Boudjada N, Hamzaoui AH. Topotactic transformation of (T-T’) La1. 8Nd0. 2CuO4: Synthesis, structure, electrical properties and oxygen diffusion pathways simulation. International Journal of Hydrogen Energy. 2021;46:26788-26800
  11. 11. Marzougui B, Houchati MI, Smida YB, Sdiri N, Marzouki R, Hamzaoui AH. Dielectric and optical properties of RE1. 8Sr0. 2CuO4±δ (RE= La, Pr, Nd). International Journal of Electrochemical Science. 2020;15:4072-4088
  12. 12. Bo L, Na L, Liping S, Qiang L, Lihua H, Hui Z. Rare-earth elements doped Nd2CuO4 as Cu-based cathode for intermediate-temperature solid oxide fuel cells. Journal of Alloys and Compounds. 2021;870:159397
  13. 13. Müller K. The unique properties of superconductivity in cuprates. Journal of Superconductivity and Novel Magnetism. 2014;27:2163-2179
  14. 14. Dahiya S, Rani K. Study of high-temperature superconductivity. Physical Sciences. 2022;1:17
  15. 15. Johrendt D. Rare earth based superconducting materials. Rare Earth Chemistry. 2022;2022:557
  16. 16. Yamamoto T, Kageyama H. Hydride reductions of transition metal oxides. Chemistry Letters. 2013;42:946-953
  17. 17. Hirsch J. Superconducting materials: The whole story. Journal of Superconductivity and Novel Magnetism. 2020;33:61-68
  18. 18. Geballe T, Kivelson S. Paired insulators and high-temperature superconductors, Pwa90: A lifetime of emergence. World Scientific. 2016;2016:127-133
  19. 19. Ruan W, Hu C, Zhao J, Cai P, Peng Y, Ye C, et al. Relationship between the parent charge transfer gap and maximum transition temperature in cuprates. Science Bulletin. 2016;61:1826-1832
  20. 20. Fournier P. T′ and infinite-layer electron-doped cuprates. Physica C: Superconductivity and Its Applications. 2015;514:314-338
  21. 21. Lv Y-F, Wang W-L, Peng J-P, Ding H, Wang Y, Wang L, et al. Mapping the electronic structure of each ingredient oxide layer of high-T c cuprate superconductor Bi 2 Sr 2 CaCu 2 O 8+ δ. Physical Review Letters. 2015;115:237002
  22. 22. Cyr-Choinière O, Daou R, Laliberté F, Collignon C, Badoux S, LeBoeuf D, et al. Pseudogap temperature T* of cuprate superconductors from the Nernst effect. Physical Review B. 2018;97:064502
  23. 23. Naito M, Krockenberger Y, Ikeda A, Yamamoto H. Reassessment of the electronic state, magnetism, and superconductivity in high-Tc cuprates with the Nd2CuO4 structure. Physica C: Superconductivity and Its Applications. 2016;523:28-54
  24. 24. Yang G, Su C, Ran R, Tade MO, Shao Z. Advanced symmetric solid oxide fuel cell with an infiltrated K2NiF4-type La2NiO4 electrode. Energy & Fuels. 2014;28:356-362
  25. 25. Wei HI, Adamo C, Nowadnick EA, Lochocki EB, Chatterjee S, Ruf JP, et al. Electron doping of the parent cuprate La2CuO4 without cation substitution. Physical Review Letters. 2016;117:147002
  26. 26. Kasem MR, Hoshi K, Jha R, Katsuno M, Yamashita A, Goto Y, et al. Superconducting properties of high-entropy-alloy tellurides M-Te (M: Ag, In, Cd, Sn, Sb, Pb, Bi) with a NaCl-type structure. Applied Physics Express. 2020;13:033001
  27. 27. Kataoka R, Taguchi N, Kojima T, Takeichi N, Kiyobayashi T. Improving the oxygen redox stability of NaCl-type cation disordered Li2MnO3 in a composite structure of Li2MnO3 and spinel-type LiMn2O4. Journal of Materials Chemistry A. 2019;7:5381-5390
  28. 28. Garcia-Barriocanal J, Kobrinskii A, Leng X, Kinney J, Yang B, Snyder S, et al. Electronically driven superconductor-insulator transition in electrostatically doped La2CuO4+ δ thin films. Physical Review B. 2013;87:024509
  29. 29. Suyolcu YE, Wang Y, Sigle W, Baiutti F, Cristiani G, Logvenov G, et al. Octahedral distortions at high-temperature superconducting La2CuO4 interfaces: Visualizing Jahn–Teller effects. Advanced Materials Interfaces. 2017;4:1700737
  30. 30. Wong-Ng W, Laws WJ, Yan Y. Phase diagram and crystal chemistry of the La–Ca–Co–O system. Solid State Sciences. 2013;17:107-110
  31. 31. Akbay T, Staykov A, Druce J, Téllez H, Ishihara T, Kilner JA. The interaction of molecular oxygen on LaO terminated surfaces of La2NiO4. Journal of Materials Chemistry A. 2016;4:13113-13124
  32. 32. Pikalova EY, Sadykov V, Filonova E, Eremeev N, Sadovskaya E, Pikalov S, et al. Structure, oxygen transport properties and electrode performance of Ca-substituted Nd2NiO4. Solid State Ionics. 2019;335:53-60
  33. 33. Ishikawa K. Crystal structure of Nd2NiO4. 08. Solid State Ionics. 2014;262:682-686
  34. 34. Li H, Cai Z, Li Q , Sun C, Zhao H. Electrochemical investigation of Pr2CuO4-based composite cathode for intermediate-temperature solid oxide fuel cells. Journal of Alloys and Compounds. 2016;688:972-977
  35. 35. Fujita M, Suzuki KM, Asano S, Koda A, Okabe H, Kadono R. μSR study of magnetism in the as-prepared and non-superconducting-La0.9Eu0.9Sr0.2CuO4. In: Proceedings of the 14th International Conference on Muon Spin Rotation, Relaxation and Resonance (μSR2017). 2018. p. 011026. DOI: 10.7566/JPSCP.21.011026
  36. 36. Kitagawa S, Higuchi T, Manago M, Yamanaka T, Ishida K, Jeevan H, et al. Magnetic and superconducting properties of an S-type single-crystal CeCu2Si2 probed by Cu 63 nuclear magnetic resonance and nuclear quadrupole resonance. Physical Review B. 2017;96:134506
  37. 37. 蘇玉, High-Pressure Synthesis, Crystal Structure and Physical Properties of Layered Manganese and Zinc Oxyhalides, 北海道大学. 2017. Available from: http://hdl.handle.net/2115/67433
  38. 38. Lenarčič Z, Prelovšek P. Charge recombination in undoped cuprates. Physical Review B. 2014;90:235136
  39. 39. Houchati MI, Houchati I, Midouni A, Ceretti M, Hamzaoui A, Paulus W. Topotactic reduction and phase transitions in (T, T′) La1.8Pr0.2CuO4. Arabian Journal of Chemistry. 2017;10:S3792-S3797
  40. 40. Wen J-J, Huang H, Lee S-J, Jang H, Knight J, Lee Y, et al. Observation of two types of charge-density-wave orders in superconducting La2-xSrxCuO4. Nature Communications. 2019;10:1-6
  41. 41. Tidey JP, Keegan C, Bristowe NC, Mostofi AA, Hong Z-M, Chen B-H, et al. Structural origins of the low-temperature orthorhombic to low-temperature tetragonal phase transition in high-T c cuprates. Physical Review B. 2022;106:085112
  42. 42. Neto EH, Comin R, He F, Sutarto R, Jiang Y, Greene RL, et al. Charge ordering in the electron-doped superconductor Nd2-xCexCuO4. 2014. DOI: 10.48550/arXiv.1410.2253
  43. 43. Bobylev I, Naumov S, Zyuzeva N, Telegin S. Study of the conductivity of perovskite-like cuprates Y (Pr) Ba2Cu3Oy and Sr2CuO3. Physics of Metals and Metallography. 2018;119:1175-1179
  44. 44. Jorgensen JD, Lightfoot P, Shiyou P, Dabrowski B. Phase Instability at the Maximum Tc in Oxide Superconductors: Phase Separation in La2CuO4+ x, Nd2-xCexCuO4, and La2-xSrxCuO4. In Advances in Superconductivity III: Proceedings of the 3rd International Symposium on Superconductivity (ISS’90), November 6-9, 1990, Sendai (p. 337). Springer Science & Business Media. December 2012
  45. 45. Grenier JC, Arrouy F, Locquet JP, Monroux C, Pouchard M, Villesuzanne A, et al. The Role of the Additional Oxygen Atoms on the Superconducting Properties of. In Phase Separation in Cuprate Superconductors: Proceedings of the second international workshop on “Phase Separation in Cuprate Superconductors” September 4-10, 1993, Cottbus, Germany (p. 236). Springer Science & Business Media. December 2012
  46. 46. Denisova L, Kargin YF, Chumilina L, Podkopaev O, Denisov V. Synthesis of Pr2CuO4 and its heat capacity in the range 364-1064 K. Inorganic Materials. 2014;50:1226-1229
  47. 47. Lahmar H, Benamira M, Messaadia L, Hamdi M, Avramova I, Trari M. Synthesis, physical and photo-electrochemical properties of Gd2CuO4. Journal of Alloys and Compounds. 2020;816:152629
  48. 48. Le Dréau L. Phase transitions and oxygen ordering in La2CoO4+ δ and (T, T')-La2CuO4: Single crystal growth and structural studies using synchrotron and neutron diffraction methods. Université Rennes. 2011;2011:1
  49. 49. de Sousa JR, Pacobahyba J, Singh M. A theoretical study of the extinction of antiferromagnetic order by holes and dilution in La2− xSrxCu1− zZnzO4. Solid State Communications. 2009;149:131-135
  50. 50. Hamad IJ, Manuel LO, Aligia A. Generalized one-band model based on Zhang-Rice singlets for Tetragonal CuO. Physical Review Letters. 2018;120:177001
  51. 51. Akpojotor G. Possible propagation of the Zhang–Rice singlet as a probable Cooper channel in the CuO2 planes. Physics Letters A. 2008;372:6992-6995
  52. 52. Jang SW, Sakakibara H, Kino H, Kotani T, Kuroki K, Han MJ. Direct theoretical evidence for weaker correlations in electron-doped and Hg-based hole-doped cuprates. Scientific Reports. 2016;6:1-7
  53. 53. Zhao H, Li Q , Sun L. Ln2MO4 cathode materials for solid oxide fuel cells. Science China Chemistry. 2011;54:898-910
  54. 54. Niemczyk A, Olszewska A, Du Z, Zhang Z, Świerczek K, Zhao H. Assessment of layered La2-x (Sr, Ba) xCuO4-δ oxides as potential cathode materials for SOFCs. International Journal of Hydrogen Energy. 2018;43:15492-15504
  55. 55. Lang W, Marksteiner M, Bodea M, Siraj K, Pedarnig J, Kolarova R, et al. Ion beam irradiation of cuprate high-temperature superconductors: Systematic modification of the electrical properties and fabrication of nanopatterns. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 2012;272:300-304
  56. 56. Smith M, Paglione J, Walker M, Taillefer L. Origin of anomalous low-temperature downturns in the thermal conductivity of cuprates. Physical Review B. 2005;71:014506
  57. 57. Liu Y, Dai H, Deng J, Li X, Wang Y, Arandiyan H, et al. Au/3DOM La0.6Sr0.4MnO3: Highly active nanocatalysts for the oxidation of carbon monoxide and toluene. Journal of Catalysis. 2013;305:146-153
  58. 58. He L, Shu Y, Li W, Liu M. Preparation of La0.7Sr0.3CoO3-δ (LSC)@ MnO2 core/shell nanorods as high-performance electrode materials for supercapacitors. Journal of Materials Science: Materials in Electronics. 2019;30:17-25
  59. 59. Varma K, Subbanna G, Ramakrishnan T, Rao C. Dielectric properties of glasses prepared by quenching melts of superconducting Bi-Ca-Sr-Cu-O cuprates. Applied Physics Letters. 1989;55:75-77
  60. 60. Özdemir ZG, Çataltepe ÖA, Onbaşlı Ü. Impedance and dielectric properties of mercury cuprate at nonsuperconducting state. International Journal of Modern Physics B. 2015;29:1550205
  61. 61. Viskadourakis Z, Radulov I, Petrović A, Mukherjee S, Andersen B, Jelbert G, et al. Low-temperature ferroelectric phase and magnetoelectric coupling in underdoped La 2 CuO 4+ x. Physical Review B. 2012;85:214502
  62. 62. Sukumar M, Agila M, Sutha A, Ravi V, Al-Enizi AM, Ubaidullah M, et al. Temperature-dependent phase transition: Structural, optical, magnetic and dielectric properties of La2CuO4 perovskite nanoparticles. Journal of Materials Science: Materials in Electronics. 2022:1-13. DOI 10.1007/s10854-022-09301-7
  63. 63. Salame P, Drai R, Prakash O, Kulkarni A. IBLC effect leading to colossal dielectric constant in layered structured Eu2CuO4 ceramic. Ceramics International. 2014;40:4491-4498
  64. 64. Al-Gunaid MQ , Saeed AM, Basavarajaiah S. Impact of nano-perovskite La2CuO4 on dc-conduction, opto-electrical sensing and thermal behavior of PVA nanocomposite films. Polymer-Plastics Technology and Materials. 2020;59:469-483
  65. 65. El Batouti M, Fetouh H. A facile new modified method for the preparation of a new cerium-doped lanthanium cuperate perovskite energy storage system using nanotechnology. New Journal of Chemistry. 2021;45:8506-8515
  66. 66. Schachinger E, Carbotte JP. Oxygen isotope effect on quasiparticle and optical properties in cuprates. Physical Review B. 2010;81:014519
  67. 67. Fausti D, Tobey R, Dean N, Kaiser S, Dienst A, Hoffmann MC, et al. Light-induced superconductivity in a stripe-ordered cuprate. Science. 2011;331:189-191
  68. 68. Homes C, Hücker M, Li Q , Xu Z, Wen J, Gu G, et al. Determination of the optical properties of La 2− x Ba x CuO 4 for several dopings, including the anomalous x= 1 8 phase. Physical Review B. 2012;85:134510
  69. 69. Li Y, Huang J, Cao L, Wu J, Fei J. Optical properties of La2CuO4 and La2− xCaxCuO4 crystallites in UV–vis–NIR region synthesized by sol–gel process. Materials Characterization. 2012;64:36-42
  70. 70. Enhessari M, Shaterian M, Esfahani MJ, Motaharian MN. Synthesis, characterization and optical band gap of La2CuO4 nanoparticles. Materials Science in Semiconductor Processing. 2013;16:1517-1520
  71. 71. Sukumar M, Kennedy LJ, Vijaya JJ, Al-Najar B, Bououdina M, Mudhana G. Structural, optical, and magnetic properties of Ca2+ doped La2CuO4 perovskite nanoparticles. Vacuum. 2019;167:407-415
  72. 72. Shi Y, Lian J, Wei X, Jin K, Song H, Wei M, et al. Study the optical properties of Pr2CuO4 thin films with different Tc0 via spectroscopic ellipsometry. Materials Research Express. 2019;6:106416
  73. 73. van't Spijker H, Simon D, Ooms F. Photocatalytic water splitting by means of undoped and doped La2CuO4 photocathodes. International Journal of Hydrogen Energy. 2008;33:6414-6419
  74. 74. Hwang C-C, Wu T-Y, Wan J, Tsai J-S. Development of a novel combustion synthesis method for synthesizing of ceramic oxide powders. Materials Science and Engineering B. 2004;111:49-56
  75. 75. Hou X, Ren J, Li F, Ma C, Zhang X, Feng H. Research progress of perovskite materials as catalysts. In: IOP Conference Series: Earth and Environmental Science. IOP Publishing; 2019. p. 032020. DOI 10.1088/1755-1315/295/3/032020
  76. 76. Li Y, Huang J, Cao L, Wu J. Optical properties in the UV–Vis–NIR region of La2-xMxCuO4-δ crystallites synthesized by sol–gel process. Journal of the Chinese Ceramic Society. 2012;40:432-435
  77. 77. Jemmali M, Marzougui B, Ben Smida Y, Marzouki R, Triki M. Polycrystalline Powder Synthesis Methods, Crystallization. London, UK: IntechOpen; 2021. pp. 1-16
  78. 78. Ji Q , Meng J, Wang H, An T, Meng J, Liu X. Ruddlesden-Popper-based lanthanum cuprate thin film cathodes for solid oxide fuel cells: Effects of doping and structural transformation on the oxygen reduction reaction. International Journal of Hydrogen Energy. 2021;46:27173-27182
  79. 79. Pederzolli D, Attfield J. Nd4Cu2O7: A copper (I) oxide with a novel cooperatively distorted T′ Type structure. Journal of Solid State Chemistry. 1998;136:137-140
  80. 80. Houchati MI, Ceretti M, Ritter C, Paulus W. From T to T′-La2CuO4 via oxygen vacancy ordered La2CuO3. 5. Chemistry of Materials. 2012;24:3811-3815
  81. 81. Houchati MI, Midouni A, Yahya M, Chniba-Boudjada N, Bardeau J-F, Hamzaoui AH. Phase diagram and transition temperatures in the system (T-T’) La2-xNdxCuO4 (x≤ 0.5). Inorganic Chemistry Communications. 2021;132:108845
  82. 82. Houchati MI. Mobilité des atomes d’oxygène dans quelques oxydes pérovskites non stoichiométriques: synthèse, structure et dynamique de réseau. Rennes. 2011;2011:1
  83. 83. Tsukada A, Krockenberger Y, Noda M, Yamamoto H, Manske D, Alff L, et al. New class of T-prime-structure cuprate superconductors. 2005. DOI: 10.1103/PhysRevB.35.8814
  84. 84. Fujimori A, Takayama-Muromachi E, Uchida Y, Okai B. Spectroscopic evidence for strongly correlated electronic states in La-Sr-Cu and Y-Ba-Cu oxides. Physical Review B. 1987;35:8814
  85. 85. Corbel G, Attfield J, Hadermann J, Abakumov A, Alekseeva A, Rozova M, et al. Anion rearrangements in fluorinated Nd2CuO3. 5. Chemistry of Materials. 2003;15:189-195
  86. 86. Kloß SD, Weidemann ML, Attfield JP. Preparation of bulk-phase nitride perovskite LaReN3 and topotactic reduction to LaNiO2-Type LaReN2. Angewandte Chemie International Edition. 2021;60:22260-22264
  87. 87. Botana AS, Norman M. Layered palladates and their relation to nickelates and cuprates. Physical Review Materials. 2018;2:104803
  88. 88. Reedijk J, Poeppelmeier K. Comprehensive inorganic chemistry II: from elements to applications. In V1 Main-Group Elem., Incl. Noble Gases V2 Transition Elem., Lanthanides and Actinides V3 Bioinorganic Fundam. and Appl.: Metals in Nat. Living Syst. and Metals in Toxicology and Med. V4 Solid-State Mater., Incl. Ceramics and Minerals V5 Porous Mater. and Nanomaterials V6 Homogeneous Catal. Appl. V7 Surf. Inorganic Chem. and Heterog. Catal. V8 Coord. and Organometallic Chem. V9 Theory and Methods Elsevier Ltd; 2013. pp. 1-7196
  89. 89. Houchati MI, Chniba-Boudjada N, Hamzaoui AH. Investigations on synthesis and electrical properties of the La1.75Nd0.1Ce0.15CuO3.5 prepared by topotactic reduction with CaH2. Journal of Coordination Chemistry. 2020;73:1881-1894

Written By

Basma Marzougui, Amira Marzouki, Youssef Ben Smida and Riadh Marzouki

Submitted: 02 October 2022 Reviewed: 28 November 2022 Published: 04 January 2023

© 2023 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution 3.0 License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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