LOW-TEMPERATURE MAGNETISM IN YBBIPT

[摘要] Positive-muon (mu+) spin-relaxation experiments have been carried out in a pressed-powder sample of the low-carrier-density heavy-electron system YbBiPt. Spatially inhomogeneous and disordered static Yb magnetism is observed below approximately 0.5 K, with a strongly reduced Yb moment of approximately 0.1-mu(B) over approximately 50% of the sample volume at T=0.06 K. Substantial mu+ spin-lattice relaxation, rarely observed in heavy-electron systems, suggests anomalously slow Yb spin fluctuations. Our data are reminiscent of mu+ behavior in spin glasses, and raise the question of whether the large low-temperature specific heat in YbBiPt is due in part to low-lying magnetic excitations.

[关键词] SPIN RELAXATION