Palladium-Iron: A Giant-Moment Spin-Glass at Ultralow Temperatures

Abstract
We report on low-frequency ac susceptibility measurements on Pd doped with 2.2, 6.8, 11, and 100 at. ppm Fe at temperatures between 79 μK and 24 mK and in fields of less than 1 mG at 3.8 G. The samples show typical spin-glass behavior with a ratio of freezing temperature to Fe concentration Tfx83 μK/at. ppm Fe. The effective moment determined from the Curie constant at T2Tf is 10μB per Fe atom.