TEMPERATURE—DEPENDENT EQUATION OF STATE AND ITS APPLICATION IN CONDENSED MATTER

Abstract

Fundamental problem in the high pressure and high temperature research is the determination of an equation of state (EOS), i.e., P-V-T relation in case of condensed matter. The study of EOS has immense importance in both the basic and the applied sciences. Various empirical as well as semi-empirical relations are available in the literature to study the P-V-T behaviour. Though the calculations of P-V from the first principle may be predicted accurately of condensed matter provided the interatomic forces are precisely known. But, the model calculations are time consuming because the calculations have to be done individually for a number of different volume. Moreover the interatomic forces are not known precisely in condensed matter. Second approach to find a correct form of EOS, which can predict the high pressure and temperature behaviour in condensed matter with a little effort may be developed involving the parameters which can be obtained from the experimental data. EOS given by Birch-Murnaghan and Vinet et al. come under this category. But, these EOS have limited application as these are non-inverted in nature. Hence, the work presented in the thesis is to search an inverted EOS which can predict the high pressure and high temperature behaviour of solids and liquids quite accurately. For a systematic presentation of the whole work, the thesis has been divided into seven chapters. The first chapter deals with an introduction to the subject matter of the thesis as well as the basic idea of the work to be presented in the other chapters. The work already done in this field is briefly reviewed and recent theoretical development related to the present work is given. Further, some EOSs available in the literature are also briefly described and discussed along with their limitations.