Low-Temperature Magnetic Susceptibilities of the Hydrated Acetates of Ni++, Co++, and Mn++

Abstract

The magnetic susceptibilities of powdered Ni${\left({\mathrm{C}}_2{\mathrm{H}}_3{\mathrm{O}}_2\right)}_2$·4${\mathrm{H}}_2$O, Co${\left({\mathrm{C}}_2{\mathrm{H}}_3{\mathrm{O}}_2\right)}_2$·4${\mathrm{H}}_2$O, and Mn${\left({\mathrm{C}}_2{\mathrm{H}}_3{\mathrm{O}}_2\right)}_2$·4${\mathrm{H}}_2$O have been measured in the liquid hydrogen and helium ranges by an ac mutual inductance method. Measurements on the cobalt salt were extended to 0.4°K revealing a sharp maximum at 0.6°K. A similar, more pronounced susceptibility peak is observed in the manganous acetate at 3.2°K. Single crystal measurements have been made on the latter salt along the monoclinic $b$ axis as well as in the ac plane. Mn${\left({\mathrm{C}}_2{\mathrm{H}}_3{\mathrm{O}}_2\right)}_2$·4${\mathrm{H}}_2$O appears to be a weak ferromagnet of the kind discussed recently by Dzyaloshinsky and Moriya.