MAGNETISM AND SPIN-GLASS BEHAVIOR OF COCL2.H2O

The magnetic behavior of CoCl2.H2O is examined for the first time. An antiferromagnetic transition occurs at 14.0 K. Below 7 K a difference between field-cooled and zero-field-cooled susceptibilities develops, and a spin glass transition appears to occur in the 6-7 K range. For large cooling fields the time dependence of the thermoremanent magnetization below T(g) is stretched exponential like. Competition between ferromagnetic and antiferromagnetic interactions in the dihydrate is presumably accentuated, and randomized, on removing half the waters, leading to a spin glass.