Gadolinium: A helical antiferromagnet or a collinear ferromagnet

Abstract

Contrary to the recent claim that gadolinium behaves as an antiferromagnet with a helical spin structure for temperatures between the spin reorientation (SR) temperature (Formula presented) and the Néel point, the ac susceptibility and low-field bulk magnetization data taken along the [0001] and (Formula presented) hexagonal directions of high-purity gadolinium single crystals over a wide range of temperatures provide ample experimental evidence in favor of the widely accepted view that gadolinium is a normal ferromagnet with a collinear spin structure in the temperature range from (Formula presented) to the Curie point (Formula presented) However, the magnetic behavior of gadolinium is complicated by a rather complex temperature dependence of the easy direction of magnetization for temperatures below (Formula presented). © 2000 The American Physical Society.