Abstract:
The A3SnO and A3PbO (A: Ca, Sr and Ba) inverse perovskite oxides have gained
immense research attention as they exhibit physical properties suitable for thermoelectric,
superconducting and magnetic devices. The emergence of stoichiometry dependent stable
ferromagnetism in these inverse perovskites has recently made these materials potential
candidates for utilization in spintronic and quantum computing devices. In the present
work, DFT based first principles total energy calculations have been employed using the
full-potential linearized augmented plane-wave method to explore the electronic,
magnetic and thermodynamic properties of pristine and intrinsic vacancy defect
containing A3SnO and A3PbO (A: Ca, Sr and Ba) compounds. The electronic structures
of these compounds are computed with the inclusion of spin orbit coupling interactions
which plays an important role in topological nature of these compounds. Furthermore, the
spin-polarization calculations have been carried out to investigate the impact of vacancy
defects on magnetic and electronic properties of these inverse perovskites. The
thermodynamic stability analysis indicated that these materials can be synthesized under
Ca/Sr/Ba rich and Sn/Pb intermediate-rich conditions. Moreover, the defect formation
energies revealed that Ca/Ba/Sr vacancies are the most stable form of vacancy defect
under oxidation (O-rich) conditions, while O and Sn/Pb vacancies are found to have
stable under reduction (O-poor) and Sn/Pb-poor conditions, respectively. Our
calculations reveal that charge neutral Sn or O vacancies can give rise to stable
ferromagnetism in non-stoichiometric A3SnO and A3PbO (A: Ca, Sr and Ba) compounds.
