THERMAL AND MAGNETIC PROPERTIES OF RARE EARTH IONS IN CRYSTALS BY CRYSTAL FIELD THEORY

Abstract

With a view to verify the accuracy of the crystalfield parameters from optical spectra for a number of rare-earth ions in anhydrous trichlorides and tribromides, hydrated ethylsulphates and sulphates, hydroxides (C3h); phosphate, vanadate and Yttrium Aluminium garnet (D2d) and thiocompounds (Oh), a study of thermal and magnetic properties is carried out in the framework of crystal field theory. Chapter I is introductory in. content and discusses the technique • employed and various physical quantities (Schottky specific heat, principal magnetic susceptibilities, spectroscopic splitting factors etc.) to be calculated in the following chapters. The crystal field potential for C3h1 symmetry ,is discussed in detail and expressed in terms of .operator eluivalents. Through-out these calculations, the exchange interaction was ignored