Magnetism and Structure of Amorphous Fe₈₀P₁₃C₇ Alloy

Abstract

Recently much work has been carried out both experimentally^1–7 and theoretically^8–11 as to whether the ferromagnetism in amorphous ferromagnetic materials is the intrinsic nature of the fused state (liquid like structure) or not. In these studies, the amorphous materials are assumed conceptually to be homogeneous in both composition and atomic arrangement. However, the phase diagrams of metals and alloys which can become amorphous are generally complicated and they undergo crystallographical transitions associated with the phase transformation on cooling from the melting points to room temperature. Therefore, it is natural to consider that even if the specimen is quenched rapidly from the liquid, the solidified state may consist of more than 2 phases existing at high temperatures which may be retained in some ways, and moreover, that this state would be highly strained and be unstable due to large quenching effect. On the other hand, it is well known that an amorphous alloy decomposes into the alloys and compounds expected from the phase diagram after crystallization at a certain critical temperature.^12,13 Therefore, it is reasonable to presume that the amorphous state cannot be uniform in composition and in both macroscopic and microscopic structure.

Detailed results and discussions on the temperature dependence of saturation magnetization, susceptibility, magnetic anisotropy, Mössbauer analysis and crystallographic structure will be published elsewhere.