Experimental study of low-temperature long-time relaxation in epoxy resin

The power(T₁,T₀,t) released after rapid temperature change from initialT₁ (1.1T₁25K) to finalT₀ (1.1T₀4.2 K) for 0.2t700 hr was measured. At low temperature,T₁,T₀<2 K, the results agree well with the tunneling theory and the corresponding density of states of two-level systems=1.0×10³⁹/Jg. For higher temperatures, significant deviations from the tunneling theory are observed.On leave of absence from the Institute of Physics of Czechoslovak Academy of Sciences, Prague, Czechoslovakia.On leave of absence from the Institute for Solid State and Material Research of Academy of Sciences of German Democratic Republic, Dresden, GDR.On leave of absence from the Technical University, Dresden, GDR.