COMPARATIVE STUDY OF EQUATION OF STATE FOR SOME IONIC CRYSTALS.

The phenomenological forms for isothermal equations of state (EOS) of solids have played a very important role in the field of high-pressure physics. An isothermal EOS is used to study the relationship between pressure P and volume compression at a given temperature. It is also used to study the isothermal bulk modulus BT and its pressure derivatives B`T and B``T, respectively. In the present study we have taken five different forms of EOS which contain B 0 and B`0 only. Using these forms we have studied the pressure-volume relationships for MgO at room temperature and at different range of temperatures. The results for pressure P, isothermal bulk modulus BT and pressure derivative B`T obtained from different equations are compared. The comparison reveals that the all EOS yield very similar results.