Temperature Variation of the Absolute Thermoelectric Power of Gadolinium

Abstract

The absolute thermoelectric power S of polycrystalline gadolinium has been measured with and without a magnetic field over the temperature ranges from 77 K to 400 K. As an effect of the magnetic field on S, a peak is observed at 220∼230 K, of which the temperature corresponds to an occuring temperature of a spin rotation from the hexagonal c-axis to a cone structure about the c-axis. The temperature variations of S and the magnetic field effect in ferromagnetic regions are analyzed in terms of the Kasuya theory based on the free electron model. At paramagnetic states, on the other hand, S increases with increasing temperature. This temperature variation is calculated taking into account unusual conductive 5d–6s bands with a 3d electron-like high density of states pointed out by Keeton and Loucks.