MAGNETIZATION CURVE OF GADOLINIUM BELOW 50 DEGREES K

The change of magnetization with temperature of gadolinium in a field of 20 kOe has been investigated up to 50°K using a sensitive technique. A departure previously found from the T3/2 variation which is followed at higher temperatures has been confirmed. This can be understood in terms of the disappearance of higher-order effects which contribute to the higher-temperature T3/2 region, and the effect of the applied field. At the lower temperatures the data come close to following a field-modified spin-wave T3/2 law. A comparison with the measured exchange interactions of terbium has also been made.