Theoretical prediction of thermoelastic properties of bismuth ferrite by a new approach

The study utilized the theory of interionic potentials and included analytical functions to account for the volume-dependent short-range force constant. Specifically, a modified version of the Shanker equation of state was used, and expressions were established for isothermal bulk modulus and its pressure derivatives. The researcher extensively analyzed the bismuth ferrite (BiFeO₃) material at pressures up to 10 GPa. The result obtained by the newly derived equation of state is compared against previously obtained equations of state, including the Shanker and Vinet equation of state and experimental data. Graphical representations demonstrate the changes in pressure, bulk modulus, and pressure derivative of bulk modulus with compression. The result shows that the newly developed equation of state provides superior outcomes compared to the Shanker and Vinet equations, particularly at high compression levels, due to the inclusion of higher-order compression terms.