Notizen: High Temperature Magnetic Susceptibility of Light Rare-Earth Tungstates

Abstract

This paper reports our results on the magnetic suscep­tibility (Χm) of light rare-earth (viz. Ce, Pr, Nd, Sm, Eu and Gd) tungstates in the temperature range of 300 to 900 K. As expected the variation of Χm with temperature obeys the Curie-Weiss law Χm = C/T - θ). The values of the Curie-constant (C), paramagnetic Curie temperature (θ) and magneton number (p) for the magnetic ions of these tungstates have been evaluated. The experimental p values are in good agreement with the theoretical values of p for these ions. Thus it is concluded that the magnetic (4f) electrons remain intact with the respective ions at high temperature and their participation in electrical conduction is improbable. Negative values of θ normally indicate anti- ferromagnetic ordering in these compounds at low tem­peratures; however in these tungstates the crystal field seems to be the prime reason for Curie-Weiss law behaviour and negative values of θ. The magnetic behaviour of light rare-earth tungstates in briefly discussed.