MAGNETIC-PROPERTIES OF THMN(12)-TYPE RCO12-XVX COMPOUNDS WITH R = Y, GD, TB, DY, HO, ER

Polycrystalline specimens of stoichometric RCo12-xVx (with R = Y, Gd, Th, Dy, Ho, Er) have been prepared and investigated by x-ray diffraction. Specimens with 2 less-than-or-equal-to x less-than-or-equal-to 3 were found to be approximately single phase (ThMn12-type structure), and used for measurement of the magnetisation, both as a function of temperature and as a function of applied magnetic fields up to 35 T at 4.2 K. From the magnetisation measurements values for the Curie temperatures and Co moments were estimated, and found to be much lower than in most R-Co intermetallics. For the compounds with a magnetic R component, values for the J(RT) coupling constants were derived. The determined J(RT) values decrease with increasing atomic number of the rare-earth component.