Prediction study of the elastic and thermodynamic properties of the SnMg2O4, SnZn2O4 and SnCd2O4 spinel oxides

We have carried out a first-principles density functional study of the structural, elastic and thermodynamic properties for the SnMg2O4, SnZn2O4 and SnCd2O4 cubic normal spinel structures. We have calculated the equilibrium structural parameters: the lattice constant and internal structural parameter. These results agree very well with experimental data. We have investigated the zero-pressure single-crystal and polycrystalline elastic constants and their related properties, confirming prior theoretical results for SnMg2O4 and predicting values for SnZn2O4 and SnCd2O4. The pressure dependence of the elastic constants Cij can be fit by a straight line over the range 0–30 GPa. Thermal and pressure effects on some macroscopic properties of SnMg2O4, SnZn2O4 and SnCd2O4 are predicted using the quasi-harmonic Debye model in which the lattice vibrations are taken into account.