Evidence of dilution-induced Griffiths instabilities in K₂Cu_1-xZn_xF₄ and Fe_1-xZn_xF₂

Authors

Christian Binek, University of Nebraska-LincolnFollow
Wolfgang Kleeman, Angewandte Physik, Gerhard-Mercator Universitat-Gesamthochschule-Duisburg, Federal Republic of GermanyFollow

Date of this Version

5-1-1995

Comments

Published by American Physical Society. Copyright 1995. Permission to use. Phys. Rev. B 51, 12888 (1995) (Rapid Communication).

Abstract

Weak quasistatic singularities are evidenced within the Griffiths regime of temperatures T_c(x)≤T≤T_c(x=0) in the diluted antiferromagnet Fe_1-xZn_xF₂, x=0.53, and in the diluted ferromagnet K₂Cu_1-xZn_xF₄, x=0.2, by measurements of the magnetic susceptibility, χ’ vs T, in zero external field. Significant deviations from classical (γ=1, for Fe_0.47Zn_0.53F₂) and nonclassical (γ≳1, for K₂Cu_0.8Zn_0.2F₄) Curie-Weiss-type behavior, χ’∝[T-T_c(x)] ^-Y, are found just below T_c(x=0) by using linear-regression data analysis.