High Pressure Study of Rare-Earth Compounds of La, PR, Yb

The work has been performed by developing a model potential which includes effects due to covalency, charge transfer due to outer most electrons of the cation and zero point energy interactions. The potential is used to derive expressions for second- and third-order elastic constants (SOECs and TOECs), thermo-physical properties and pressure derivatives of SOECs. The computed results are capable to explain successfully the SOECs,Cauchy's discrepancy in SOECs and their pressure derivatives, phase transition pressures, volume collapse, and thermal properties. The present results are close to experimental data and better than those computed earlier by others. Present model potential can be used for the similar properties of other compounds too.