Pressure-induced band gap shift and enhanced optical properties of quaternary Heusler TaAlCuCo: DFT study

Abstract

The following work presents a theoretical study on new quaternary Heusler compounds called TaAlCuCo under varying pressures from 0 to 100 GPa. The study comprehensively investigates the material's structural, elastic, mechanical, electronic, optical, and vibrational properties. The results reveal that as the applied pressure increases, the lattice parameters of TaAlCuCo decrease from 6.058465 to 5.476836 Å. Furthermore, the material exhibits desirable characteristics such as ductility, metallic bonding, and stability even under high pressure. Notably, TaAlCuCo demonstrates anisotropic behavior, indicating that its properties vary depending on the measurement direction. The study also observes a widening of the material's bandgap from 0.010 to 0.333 eV with increasing pressure, suggesting a decline in conductivity. Additionally, TaAlCuCo exhibits favorable optical properties, including a high refractive index, absorption, reflectivity, and conductivity, thereby indicating its potential as a UV filter and for use optoelectronic devices.