Magnetization of the AgMn spin glass in high magnetic fields

High magnetic field (up to 35T) magnetization measurements of five Mn doped Ag spin glass samples have been measured from 50K, well above their respective glass temperatures, to 4.2K. The Mn concentrations varied between 0.4% to 2.7% Mn. Of these samples, the one with 2.7% Mn was co-doped with 0.27% Pt and a second with 1% Mn was co-doped with 2% Au. The data were fitted to a Brillouin function with an effective interaction temperature, T_c, in the denominator given, i.e., the denominator was T-T_c. All data were well fit at all temperatures with the Brillouin function. It was found all had effective interaction temperatures, the T_c, that varied approximately linearly with temperature. The variation went from positive at the highest temperatures (consistent with ferromagnetic interactions) to negative at the lowest temperature (consistent with antiferromagnetic interactions). Note the highest temperatures were 50K, well above the glass temperatures for all the samples. In addition, the deviations between the measured data and the Brillouin function fit as a function of field oscillated in sign at all temperatures and were similar for all the samples. .