Anomalous Magnetization of GdB₆ in High Magnetic Field

抄録

High field magnetization of antiferromagnetic GdB₆ up to 520 kOe is studied. The saturation magnetization is obtained around 490 kOe at 1.3 K and the system can be regarded as a typical cubic antiferromagnet. Anomalous two small magnetization jumps are found near the saturation field H_c. They are explained by the local spin-flip of the disordered Gd spin located at the B₆ cluster site. The Gd spin at the disordered site couples with surrounding host spins with the exchange energy of −0.67 K which is about 14% smaller than the antiferromagnetic host spin coupling.