Sputtering yield measurements of laser ablated Mg-alloy correlated with surface, structural and mechanical modifications

Abstract Sputtering yield of laser ablated Mg-alloy has been measured by Quartz Crystal Microbalance at various fluences ranging from 11.6 to 44.2 J/cm2, under two different environments of Ar and O2· The sputtering yield initially increases from 14.58 × 1014 to 23.49 × 1014 and from 4.5 × 1014 to 22.60 × 1014 (atoms/pulse) by increasing fluence and then decreases upto a value of 19.78 × 1014 and 19.94 × 1014 (atoms/pulse) at the maximum fluence, under Ar and O2 environment respectively. Scanning Electron Microscope analysis reveals the formation of cones, cavities, droplets, ripples and island like structures on the irradiated Mg surface. Surface profilometry analysis reveals that the crater depth of laser irradiated Mg-alloy ranges from 188 to 209 µm. It initially increases by increasing laser fluence and afterwards, decreases at the maximum fluence. Energy Dispersive X-ray spectroscopy (EDX), X-Ray Diffraction analysis (XRD) and Ultraviolet-Visible (UV-VIS) spectroscopy confirm the oxide formation for the laser treated target of Mg in O2. The Vickers Micro-hardness testing reveals that hardness of laser irradiated Mg-alloy is increased by increasing fluence. The surface structures, crater depth and hardness of laser irradiated Mg-alloy are strongly dependent upon laser fluence and are correlated with sputtering yield measurements.