Premium
Cluster Theory of a Dilute Antiferromagnet. Application to the Mn 1– c Zn c F 2 System
Author(s) -
Dzyub I. P.
Publication year - 1974
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2220610202
Subject(s) - antiferromagnetism , excitation , cluster (spacecraft) , physics , spin (aerodynamics) , coupled cluster , atom (system on chip) , spectrum (functional analysis) , condensed matter physics , range (aeronautics) , atomic physics , transverse plane , quantum mechanics , materials science , molecule , thermodynamics , structural engineering , computer science , embedded system , engineering , composite material , programming language
A cluster theory of a dilute antiferromagnet which simultaneously takes into account the fluctuations in the longitudinal and transverse part of the exchange interaction is proposed. The present theory allows to describe the dependence of the line shapes of the spin excitation spectrum on the nonmagnetic atom concentration and the wave vector. A comparison with experimental results indicates that the predictions of the theory are valid in a wide range of concentrations when the long‐range order persists. It is pointed out that the coherent wave approximation accounts for the gross behaviour of the spin excitation spectrum. It is demonstrated that the results of the cluster theory are close to those of the coherent potential approximation, but more transparent and more suitable for comparison with experiment.