Czechoslovak Journal of Physics 46, 2239 (1996)
A. Nittke and P. Esquinazi
Abstract
We have measured the heat release of pure (6N) aluminium in the time range from 5h to 300h after cooling it from 85K to 200mK, in the normal and superconducting states. We measured a heat release that resembles quantitatively that from vitreous silica (SiO2) at times t > 4 x 105 s indicating the existence of tunneling systems in agreement with previously published acoustic measurements. The time dependence of the heat release in Al is, however, weaker as that found in amorphous materials. No difference in the heat release has been measured in the normal and superconducting states.
