MAGNETIC-PROPERTIES OF RARE-EARTH COMPOUNDS OF THE RCO(10)MO(2) TYPE

The magnetic properties of the tetragonal ThMn12-type RCo 10Mo2 compounds have been investigated by means of magnetic measurement and x-ray diffraction. It is found that the Co moment is roughly the same in all RCo10Mo2 compounds (0.9 μB/Co), excepting CeCo10Mo2 (0.7 μB/Co). It is also found that the Co sublattice displays easy c-axis magnetization. Nonaxial behavior at room temperature is observed only for SmCo10Mo2, whereas in ErCo10Mo2 a spin reorientation occurs from axial to planar magnetization upon cooling below Tsr=125 K. These results suggest that the A02 term, mainly responsible for the rare-earth-sublattice anisotropy has the same sign as in the R2Fe14B series (A0 2≳0). This is in contrast to other ThMn12-type compounds (RFe10V2, RFe11Ti) where it is generally assumed that A02<0. The intersublattice coupling of ErCo10Mo2 has been determined by means of the high-field free-powder method.