Research Papers in Physics and Astronomy
Date of this Version
April 1998
Abstract
The temperature dependence of the uniform susceptibility χ of diluted two-dimensional Ising antiferromagnets Rb2Co1-xMgxF4, 0<~x<~0.4, is investigated in the limit of vanishing external field. Data for x=0.15 are compared with those obtained for x=0 and 0.4 by Breed et al. (1969) and Ikeda (1983), respectively. Whereas in the pure case, x=0, Fisher’s (1962) “energetic contribution” dominates, Aharony et al.’s (1979,1986) “random contribution” becomes increasingly important with increasing x. Taking into account both terms not only with respect to the global ordering temperature TN(x), but also in relation to the “local” phase transition temperatures TN′ throughout the Griffiths regime, TN(x)<~TN′<~TN(0), a satisfactory quantitative description of χ vs T is deduced for any x above the percolation threshold. ©1998 The American Physical Society
Comments
Published by American Physical Society. Copyright 1998. Permission to use. Phys. Rev. B 57, 7791 (1998).