Two Successive Transitions in Uniaxially Anisotropic Spin-Glasses

Abstract

Longitudinal ($\ensuremath{\parallel}c$) and transverse ($\ensuremath{\perp}c$) ac susceptibilities have been measured on single crystals of the Ising-type spin-glass ZnMn and the $\mathrm{XY}$-type spin-glass CdMn. A clear cusp is observed in each direction at different temperatures for ZnMn with 270, 390, and 600 ppm Mn. These behaviors indicate that two successive transitions occur in these systems as was suggested by mean-field theories for anisotropic spin-glasses. The phase diagram obtained is in accordance with the theoretical one.