Magnetoresistance and magnetization study of thulium

Abstract

The results of a detailed resistance and magnetization study of thulium are presented. From these results we derive a magnetic phase diagram for thulium. The $c$-axis component of the resistivity is strongly affected by the superzone energy gaps induced by the modulated ordering of the magnetic moments in thulium in agreement with earlier experiments. According to the theory of Elliott and Wedgwood the superzones introduce an increase of the resistivity proportional to the magnetization just below ${T}_{N},$ whereas experimentally the change is found to be quadratic in the magnetization. Except for this principal discrepancy, the experimental results are well accounted for when combining a variational calculation of the resistivity with the magnetic model derived for thulium from neutron scattering experiments.