Electronic, optical and mechanical properties of MAs2 (M = W, Cr, Mo): a first-principles study

Abstract

The structural, elastic, mechanical, optoelectronic, and Debye temperatures of \({\text{MAs}}_{2}\) (M = W, Cr, Mo) were explored at ambient pressure using first-principles calculations. Lattice constants and cell volume are calculated to be in good consistent with other findings. We investigated the mechanical properties of \({\text{MAs}}_{2}\) materials using elastic moduli, the machinability index, and Vickers hardness. Poisson’s and Pugh’s ratios indicate that \({\text{WAs}}_{2}\) material is ductile, whereas \({\text{CrAs}}_{2}\) and \({\text{MoAs}}_{2}\) are brittle at ambient pressure. Analyzing electronic properties offers crucial support for assessing optical performance. In the higher energy range, the refractive index value falls and flattens. Due to their high reflectivity, these phases are excellent candidates for solar heating reduction in the infrared and ultraviolet wavelength regions. The minimum thermal conductivity values for \({WAs}_{2}\), \({CrAs}_{2}\), and \(Mo{As}_{2}\) are 0.571, 0.732, and 0.666, respectively, making them attractive thermal insulators above their Debye temperatures (\({\theta }_{D}\)). Melting temperatures show that \(Cr{As}_{2}\) melts at 1389.12 °C, \({MoAs}_{2}\) at 1587.60 °C, and \({WAs}_{2}\) at 1648.86 °C. It indicates that \({WAs}_{2}\) is the most thermally stable of the three compounds, whereas \(Cr{As}_{2}\) is the least. Lastly, we anticipate that the present findings will have profound implications for future studies of various aspects of related materials.