Abstract: Magnetostriction and magnetization of CeFe2

Abstract

While investigating the high field magnetostriction of the highly magnetostrictive cubic laves phase compounds of the type RFe2 a sharp increase in the magnetostriction of polycrystalline CeFe2 was observed at fields of around 3 T and at temperatures below 150K. The first order change in strain increases with decreasing temperature and at 5K it amounts to approximately 150×10−6 which corresponds to a 200% increase in the parallel magnetostriction. The field at which the transition occurs decreases slowly with decreasing temperature. Magnetisation curves also show signs of a first order increase at the same fields but the change in magnetisation is only of the order of 8% at 5K. Above approximately 150K the easy-direction of CeFe2 changes1 from [100] to a non-symmetry direction of the type [uuw]. This can be accounted for if the third order cubic anisotropy constant (K3) is significant. A tentative explanation for the observed discontinuities is presented in terms of first-order rotations of the magnetisation vector, made possible by relatively large values of K3. 1U. Atzmony and M. P. Dariel, Phys. Rev. B. 13, 4006 (1976).