Prediction study of the elastic and thermodynamic properties of the SnMg2O4, SnZn2O4 and SnCd2O4 spinel oxides (original) (raw)

We have carried out a first-principles density functional study of the structural, elastic and thermodynamic properties for the SnMg 2 O 4 , SnZn 2 O 4 and SnCd 2 O 4 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 SnMg 2 O 4 and predicting values for SnZn 2 O 4 and SnCd 2 O 4. The pressure dependence of the elastic constants C ij can be fit by a straight line over the range 0-30 GPa. Thermal and pressure effects on some macroscopic properties of SnMg 2 O 4 , SnZn 2 O 4 and SnCd 2 O 4 are predicted using the quasi-harmonic Debye model in which the lattice vibrations are taken into account.