Magnetic properties of Sm(Co,Cu) alloys. II. Coercivity mechanism

Abstract

A theoretical interpretation of the hard‐magnetic properties of Sm(Co,Cu)_z compounds with 5<zzz≳6.0, two simplified models are considered. The first is a one‐dimensional system consisting of microscopic precipitates of an Sm₂Co₁₇‐like phase lying in a lattice‐strained matrix of Sm(Co,Cu)₅. The pinning‐type coercivity and its angular and temperature dependences are considered. The second model evaluates the interaction between macroscopic Sm₂Co₁₇‐like precipitates and an Sm(Co,Cu)₆‐type matrix typical of composition z≳6.0. The effect upon the demagnetization curves is illustrated. Despite their simple nature, both models allow order of magnitude agreement with experimental results. In addition a quantitative understanding of the influence of the various features involved is provided.