Magnetization of the Rare-Earth Manganese Compounds R6Mn23

Measurements have been made of the magnetic moments of compounds of the type R6Mn23, where R is a rare-earth ion. Determination of the saturation moments of Mn with nine of the rare earths (Sm, Nd, Gd, Tb, Dy, Ho, Er, Tm, and Lu) show that, with one exception, the rare-earth and manganese moments are antiparallel; only in the gadolinium manganese compound is there complete ferromagnetic coupling. From the moment of Lu6Mn23 one derives the moment of 0.4μB per manganese atom. The measured moments of the other compounds agree closely with those calculated assuming a moment of 0.4μB for Mn and the normal moment of gJ for the appropriate rare-earth atom.