THERMODYNAMIC PROPERTIES OF MOLECULAR ORIENTATIONAL GLASSES WITH INDIRECT INTERACTION

Abstract

The general regularities of the behaviour of heat capacity and thermal expansion of solutions of substances with simple linear molecules in solidified inert gases at concentrations of about 1 mol % when the direct quadrupole interaction between impurities does not play an important role are discussed. In such solutions indirect (static and dynamic) interactions between impurity molecules (rotators) are dominant. The static interactions are realized through deformation fields produced by impurities in a lattice. The dynamic ones are performed by the phonon exchange between impurity molecules. Under certain conditions the indirect interactions mentioned lead to stochasticity of an energy spectrum of the subsystem of rotators and the appearance of an orientational glass–like state. Special attention is paid to the behaviour of the systems in which an energy spectrum of rotational motion of impurity molecules is determined by intramolecular degrees of freedom. The experimental results of the studies of thermal properties of N 2 and O 2 in solid Ar and Kr are presented.