Magnetic and crystallographic properties of R2-xPrxCo14B (R = Tb, Dy, Ho and Tm)

R2Co14B systems do not form in the characteristic Nd2Fe14B structure for rare earths heavier than Tb. They can be formed in this structure in the Dy, Ho and Tm systems when some of the heavy rare earth is replaced by Pr. The amount of Pr needed to stabilize the structure is the larger the smaller the heavy rare earth. All systems studied exhibit uniaxial anisotropy. Magnetizations and anisotropy fields increase with increasing x in the R2-xPrxCo14B systems. Evidence of spin reorientation is observed at temperatures ranging from 420 to 790 K. Introduction of Pr in place of R reduces the spin-reorientation temperature for R = Tb but increases it for R = Dy, Ho and Tm.