MAGNETISM AND SPIN-GLASS BEHAVIOR OF FECL2-CENTER-DOT-H2O

The magnetic behavior of FeCl2 . H2O is examined for the first time. T he susceptibility exhibits a sharp peak at 20.4 K which may be cusp-li ke, and which is very different from the antiferromagnetic maximum in the dihydrate. Field-cooled and zero-field-cooled susceptibilities dif fer at low temperatures but become coincident near 24 K. The thermorem anent magnetization shows time dependence below 20 K. Competition betw een ferromagnetic and antiferromagnetic interactions in the dihydrate is presumably accentuated, and randomized, on removing half the waters , leading to a spin glass.