MACROSCOPIC MAGNETIC-ANISOTROPY IN SPIN-GLASSES - TRANSVERSE SUSCEPTIBILITY AND ZERO-FIELD NMR ENHANCEMENT

Low field NMR and transverse susceptibility data in CuMn spin glass confirm that all the remanence sigma is involved in the magnetization rotation. The quasi equilibrium magnetostatics of sigma is characterized by uniaxial (H//a//x) and unidirectional (H//d) anisotropy fields determined by either experiment. The width DELTA H of the hysteresis cycle, when detected, is correlated with H//a//x, although the reversals of sigma are not fully understood. The anisotropy energy is found two orders of magnitude larger in AuFe than in CuMn.