Effect of the negative chemical pressure on physical properties of doped perovskite molybdates in the framework of DFT method

Abstract

In present study, the negative chemical pressure effect on SrMoO3 molybdate system has been demonstrated with the help of substitution based strategy employing density functional theory (DFT) for the first time. We have observed that it is possible to tune band structure (BS) in a controlled manner by introducing higher ionic Barium (Ba) to the lower ionic Strontium (Sr) site by controlling doping content. We have noticed an interesting correlation among BS, covalency strength and negative chemical pressure. Equally important, elastic, mechanical and direction dependency of our system also can be correlated with negative chemical pressure and can be tuned effectively with doping amount. It can be noticed that the anisotropy of our system under study is significantly dependent on elastic constant C11 and prominent anisotropy can be observed in the Poisson ratio than the Shear modulus in all the cases. We have predicted an effective way of describing the phase and compression of a disordered system using elastic constant employing the theoretical and graphical (2D and 3D) anisotropy measurement techniques which can be a guidance for future research using DFT.