MAGNETIC PROPERTIES AND PD-H MISCIBILITY GAP IN NI/PD COMPOSITE FINE PARTICLES

The magnetic and structural properties of Ni fine particles coated with Pd were investigated in hydrogen atmospheres by means of in situ magnetometry and in situ x‐ray diffractometry. The x‐ray diffraction patterns in hydrogen atmospheres show that the width of the plateau in the Pd–H phase boundary (miscibility gap) narrows with decreasing Pd thickness, which is reminiscent of nano‐crystalline Pd. At room temperature, the magnetization in hydrogen atmospheres shows a steep saturation and a small decrease in the residual magnetization, indicating that the interface magnetic anisotropy is reduced by the hydrogenation.