LAUSR

Abstract The effects of Fe substitution on the structural and magnetic properties of NdCo 12- x Fe x B 6 (0 ≤  x  ≤ 2.3) series of compounds have been investigated. Fe for Co substitution in NdCo 12- x Fe x B 6 leads to an anisotropic expansion of the unit cell: the initial growth along the c -axis is more rapid than that in the basal-plane. All of the compounds are ferromagnets and exhibit a spin reorientation transition. The Curie temperature, T C , shows a monotonic decrease with increasing Fe concentration from 155 K to 115 K as x increases from 0 to 2.3. A decrease of the spontaneous magnetization, M S , is found to occur upon Fe for Co substitution.