Effects of negative chemical pressure on the structural, mechanical, and electronic properties of molybdenum-doped strontium ferrite

Abstract

In this research, the effects of negative chemical pressure on various physical properties of SrFeO3 were investigated by partially substituting larger Mo at smaller Fe-site. The calculated lattice parameters exhibited a linear increasing trend according to the Vegard’s rule with increasing doping of Mo confirmed the existence of negative chemical pressure within the compound. The calculated formation enthalpy as well as elastic constants that satisfied the Born criteria ensured the structural and mechanical stability, respectively, of our system under varied doping of Mo. In addition, the mechanical properties, including the elastic moduli, Pugh’s ratio, Poisson’s ratio, hardness, and machinability index, were also successfully investigated and noticeably affected by the negative chemical pressure induced by doping. Moreover, it would be possible to tune the band structure of SrFeO3 by partially substituting Mo at Fe-site. The accumulation of electron carriers in the vicinity of Fermi level was increased with the increment of doping level, which was justified by DOS calculations. More interestingly, the flat bands close to the Fermi level predicted the superconducting nature of this compound (both undoped and doped) under study.