Measurements of 1/f Noise in CuMn and AgMn Thin Films*

We have measured the 1/f noise in the spin glass state of CuMn and AgMn thin films. The Mn concentrations we have investigated are approximately 11% Mn for the CuMn samples studied and 12% in the case of AgMn. Our CuMn results are consistent with previous measurements that have demonstrated low-frequency resistance fluctuations increase in magnitude as a spin glass is cooled below the glass temperature T_g, but with some significant differences. Similar to the CuMn, we find a rather abrupt increase in the 1/f noise when the AgMn is cooled to below the glass temperature. A comparison of the noise between the two systems and previous measurements will be presented.