HEAT-CAPACITY OF KR-O2 SOLUTIONS AT HELIU M TEMPERATURES

In the region of temperatures 0.5-10 K and oxygen concentration = 0.26 -10 mol. % the heat capacity C of solid solutions (Kr-nO2)-O-16 at equ ilibrium vapour pressure has been investigated. The contribution DELTA C(T) to the heat capacity that Is due to the spin-rotating degrees of freedom is derived. At low impurity concentrations (n = 0.26 mol. %) i n the region of 1 K the maximum of DELTAC(T) is observed; its position is very dose to that of the DELTAC(T) maximum of the Ar-0.13 mol.% O- 16(2)2 solution. The comparison of the experimental data with theoreti cal model is carried out. At higher oxygen concentrations the glass-li ke behavior of the heat capacity of Kr-O2 solutions is less pronounced than in the case of Kr-N2 solutions. An explanations of this differen ce has been proposed.