Spin glass phase in spin-density-wave Cr-Co alloys

A spin glass (SG) phase was observed in the spin-density wave (SDW) alloys Cr1-xCox at high Co concentrations (x greater than or equal to 13%). After zero-field cooling, the temperature dependence of the magnetization M(T) of Cr0.87Co0.13 and Cr0.85Co0.15, measured in an applied field H = 100 Oe wit h a SQUID magnetometer, exhibits a low T maximum, characteristic of a SG. C ooling in the measuring field, however, gives quite a different behavior. T he field dependence of the magnetization M(H) is nonlinear, with a pronounc ed hysteresis. A strong time relaxation M(t) is also an indication of a SG phase. SG in Cr1-xCox is formed at high impurity concentrations, possibly d ue to clustering of the magnetic impurities. (C) 2001 American Institute of Physics.