Magnetocrystalline Anisotropy and Exchange Interaction in YCo_12-xTi_x Compounds

Magnetic and structural properties of YCo_12-xTi_xcompounds have been investigated by x-ray diffraction and magnetic measurements. X-ray diffraction patterns of aligned powder samples indicate that the easy magnetization direction at room temperature is along the c-axis for all the compounds. The lattice parameters increase monotonously while Curie temperature T_C decreases with increasing Ti content. It was found that all the compounds investigated are strong ferromagnets by analysis of magnetic moments using a magnetic valence model. The values of anisotropy fields B_a at room temperature and 1.5K decrease with increasing x. The easy-axis anisotropy of the YCo_12-xTi_xcompounds is mainly contributed by the Co atoms at 8i sites according to the individual-site-anisotropy model.