Résumé:
In our work, we studied the structural, elastic and electronic properties of cubic perovskites CaSnO3, SrSnO3 and BaSnO3. We used the Plane Wave Augmented and Linearized with Total Potential (FP-LAPW) method within the framework of the DFT density functional theory implemented in the Wien2k code. The exchange and correlation potential was treated by different approximations WC-GGA and TB-mBJ. The results of the calculation showed that these perovskites are indirect gap semiconductors (Γ-M). The top of the valence band resulting mainly from the p states of the oxygen O atom, and the bottom of the conduction band resulting mainly from the d states of the A atom with respect to SrSnO3 and BaSnO3 perovskites, and s-states of the A atom with respect to the CaSnO3 compound. CaSnO3, SrSnO3 and BaSnO3 are mechanically stable and rigid where the degree of rigidity of these materials decreases in the following order: CaSnO3, BaSnO3, SrSnO3. We have also classified them, according to the Poisson modulus and the Pugh ratio, into brittle materials, except SrSnO3 which is a ductile material. We also compared our results with available theoretical and experimental results.
