Curie Temperature and Critical Concentration of a Diluted Amorphous Ferromagnet‐ DRPHS Model

Abstract

and Sektion Physik der Technischen UniversitPt Dresden (c) Curie Temperature and Critical Concentration 1) 2) of a Diluted Amorphous Ferromagnet -DRPHS Model BY W. NAZAREWICZ (a), A. ZAG6RSKI (a), A. R. FEFCHMIN (b), and S. KOBE (c)Ferromagnetism of materials randomly diluted with non-magnetic atoms was subject of many experimental and theoretical studies. Although relevant experiments were performed on crystalline a s well as on amorphous materials, the theory was confined to random dilution of systems with regular lattices, the randomness of interactions being sometimes introduced /l/. However, the related theoretical problems of percolation were recently developed so a s to cover the topologically disordered systems /2 to 7/. The existing experiments / 8 , 9/ were mostly interpreted in t e r m s of actual theories of dilution based originally on the concept of crystallinity of the material, i. e., on the underlying regular lattice. More specifically, for the purpose of calculation the magnetic

Cluster Identities for the Ising Model as a Basis for Simple Effective Field Approximations Discerning between Various Lattices with the Same Coordination Number

“…I n the early sixties exact identities for Ising and other classical spin correlations have been derived 11,2]. They proved very useful as a basis for approximations [3 t o 51 subsequently applied t o various problems, such as magnetism of films and surfaces [B, 71 and magnetically diluted amorphous systems [8,91. The apparent success of these approaches has t o be attributed t o their conceptual and algebraic simplicity, comparable t o that of t h e Weiss molecular field (WMF) method.…”