Magnetic Properties of Terbium Metal

Abstract

Results of magnetic measurements on metallic terbium over the temperature range from 4° to 375°K and in fields ranging from 50 oersteds to 18 000 oersteds are reported. The metal is found to have a paramagnetic Curie point of 237°K. Tests with fields of from 50 to 800 oe indicate an order-to-disorder transition at approximately 230°K which is evidently a Néel point. It appears that terbium has a weakly bound antiferromagnetic ordering for temperatures between 218° and 230°K, this ordering being gradually changed to ferromagnetic in fields exceeding 200 oe. Below 218°K the metal is ferromagnetic. The magneton numbers obtained from the paramagnetic susceptibility measurements and from the extrapolated ferromagnetic saturation moment are in good agreement with values calculated for the free ion.