Magnetostriction and magnetisation of CeFe2

Abstract

Magnetostriction and magnetisation measurements are made on a polycrystalline sample of the cubic Laves phase compound CeFe, in pulsed magnetic fields up to 18 T and over the temperature range 5 to 300 K. A sharp increase in magnetostriction is observed at fields of about 3 T and a t temperatures below 150 K. The magnitude of the first-order change in strain increases with decreasing temperature and a t 5 K i t amounts to approximately 150 x which is a 200% increase in the para.lle1 magnetostriction. The critical field for the transition decreases slowly with decreasing temperature. The corresponding change in magnetisation is of the order of 8% a t 5 K. It is proposed that this transition corresponds to a first-order rotation of the magnetisation vector due to a particular combination of anisotropy constants. I n particular, the effect of the eighth-order constant K3 which also leads to a non-symmetry easy direction above 150 K, is likely to be important. Des mesures de magnbtostriction et d'aimantation ont B t 4 effectuees sur un Bchantillon poly-Nous en concluons que cette transition correspond A une rotation de premier ordre du vector d'aimantation, due A une wmbinaison particulibre de constantes d'anisotropie. En particulier, l'effet de la constante de huitibme ordre K3 qui conduit h i aussi b une direction facile de nonsymmbtrie au-dessus de 150 K, est sans doute important.