Paramagnetic relaxation in some diluted and undiluted chromium, copper and manganese salts at very low temperatures

Abstract

In this paper, which may be considered as a sequel to an earlier one, in which measurements on a number of iron ammonium alums have been treated, we present paramagnetic measurements, performed on some diluted chromium potassium alums and on diluted and undiluted manganese ammonium and copper potassium tutton salts at very low temperatures. The salts were placed in a magnetic field, consisting of a constant part and an alternating part of low frequency. The results on the highly diluted salts and on the undiluted manganese tutton salt may in a good approximation be described by Casimir and Du Pré's formulae with one relaxation time. Deteriorated samples deviate largely from these formulae. The relaxation parameters of the manganese salts have about the same dependence on temperature, magnetic field and concentration of the magnetic ions as those of the iron alums; this is not quite the case with the parameters of the other examined samples. In the discussion a rough and provisional explanation of the data of this paper and earlier papers is presented.