Frequency dependence of magnetic AC susceptibility in CuMg spin glass

The AC susceptibility of a single crystal CuMg spin glass was measured. Both χ’ and χ’’ were measured as a function of frequency in a SQUID Magnetometer. The spin glass was a 8% Mn sample mixed with Cu with a measured glass temperature of 42 K. Frequencies from 0.1 Hz to 250 Hz were explored at temperatures ranging from 16 -32 K. The measurements displayed a largely monotonic relationship between both suseptibilites and frequency. Our results can be interpreted in terms of a rugged free energy landscape, with the frequency response associated with relevant barrier heights that govern spin glass dynamics. These experiments are directed at understanding the frequency dependence of experiments exhibiting rejuvenation and memory.