High Pressure Effect on Structural, Electronic and Elastic Properties of Topological Half- Heusler LaPdBi Compound

The elastic, electronic and structural properties of LaPdBi compound were investigated by first-principles density functional theory based on density functional theory (DFT). The lattice constant, energy gap, density of states, band structure, bulk modulus and its first pressure derivative are calculated using the generalized gradient (GGA) approximation. There is a good agreement between our results and available experimental and theoretical values. The lattice constant and energy gap of LaPdBi using the GGA approximation are 6.98 Ǻ and 0.315 eV respectively in fair agreement with experimental results. We calculated bulk modulus and its first pressure-derivative to be 72.25 GPa and 4.43 respectively. We have studied the effect of applying high pressure up, to 80 GPa, on both of the energy gap and bulk modulus of LaPdBi. For example they reached 0.425 eV and 520 GPa respectively at 80 GPa. The effect of high pressure on the density of states is included in this study.