Umm-I- Kalsoom

By Nisar Ali, Umm-i-Kalsoom, Shazia Bashir and Narjis Begum

The structural modifications of KrF excimer laser-ablated zirconium (Zr) have been investigated in correlation with its surface and mechanical properties after ablation in deionized water and ethanol. KrF excimer laser of pulse duration of 20 ns, wavelength of 248 nm, and repetition rate of 20 Hz has been utilized for this purpose. Irradiation of Zr was carried out for varying number of laser pulses ranging from 500 to 2000 for laser fluence value of 3.6 J/cm2. The structural and chemical analyses were performed by using X-ray diffraction (XRD), Raman spectroscopy, and energy dispersive X-ray spectroscopy (EDS) techniques. Scanning electron microscope (SEM) and Vickers hardness tester were utilized for the analysis of surface morphology and hardness of laser-irradiated Zr targets. Presence of surrounding liquids played substantial role in structural, chemical, and mechanical modifications of Zr targets after irradiation. Pressure gradients and convective bubble motion owing to the confinement effects of the surrounding liquids, several thermal and chemical phenomena produced by heating through laser at the solid-liquid interface results in the generation of various hydrides and oxides of Zr, which are responsible for the development of various surface features and increase in hardness of irradiated Zr.

Part of the book: Laser Ablation