Magnetic properties of R2Co14B (R = rare earth)

Magnetic and crystallographic properties of R2Co14B (R=R.E.) and Pr2(Co1-xTx)14B (T=Cr, Mn, Fe and Ni) are studied. In the cases of R=Y, La, Pr, Nd, Sm, Gd and Tb in the specimens with nominal composition of R2Co14B, the R2Co14B phase exists. Magnetic moment of Co atom is 1.22 μBfor Pr2Co14B and Nd2Co14B. Magnetic anisotropy constants are determined at various temperatures for a field-aligned specimen of Pr2Co14B. The spin axis of R2Co14B (R=Pr and Nd) changes from c-axis to c-plane at 760 K and 610 K respectively and that of Sm2Co14B remains in the c-plane for all temperatures. The tilting phenomena of magnetic moment is found for Pr2Co14B below TSR= 272 K and discussed phenomenologically. Hysteresis curves for the field-aligned Pr2Co14B (particle size m) are also measured.