We report dc-magnetization measurements on Ag:Mn and Cu:Mn spin glass samples (1-8% Mn concentrations), at temperatures of 4-30 K, and in fields of 4-400 Oe. The temperature at which the magnetization of a particular sample becomes reversible (TR) is found to depend on the homogeneity of the sample, and on the magnitude of the measurement field. Inhomogeneous samples showed irreversible behavior far above the glass temperature (T R≃1.5 TG). After annealing, these samples showed a sharper peak in the magnetization at TG∼TR. We feel this is strong evidence toward a unique glass temperature for homogeneous samples in low fields. In higher fields (400 Oe) we found reversibility to begin at a temperature less than the magnetization peak (TR≃0.9 TG for 4% Ag:Mn).
ASJC Scopus subject areas
- Physics and Astronomy(all)