Elastic, electronic and thermoelectric properties of Sr3MN (M = Sb, Bi) under pressure

Abstract We have performed first-principles calculations to study the structural, elastic, electronic and thermoelectric properties of Sr 3 M N ( M  = Sb, Bi) under pressure. The optimized lattice parameters are in good agreement with the available experimental and theoretical measurements. Brittle to ductile transition occurs at 15 GPa and the hardness of both compounds decreases with the increase of pressure. The band gap slightly reduces with pressure and both compounds exhibit semiconducting nature for TB-mBJ potential. The density of states increases slightly at the Fermi level. The inclusion of the spin-orbit coupling effect reduces the band gap of Sr 3 BiN. The calculated Seebeck coefficient for Sr 3 SbN and Sr 3 BiN at 15 GPa and 600 K are 257 and 142  μ V/K, respectively. The calculated lattice thermal conductivity of both compounds decreases with the increase of pressure, as phonon scattering increased. The predicted thermoelectric figure of merit ( ZT ) for Sr 3 SbN and Sr 3 BiN at 15 GPa and 600 K are 0.71 and 0.63, respectively. The obtained thermoelectric properties at high pressure making them suitable for thermoelectric device applications.