High-field magnetization of distorted triangular lattice antiferromagnet RbCoBr3

High-field magnetization measurements were performed on a distorted triangular-lattice antiferromagnet, RbCoBr 3 . The magnetization curve shows anomalies characterized by two peaks of d M /d H . The temperature dependences of these peak positions approach the magnetic phase transition points at H = 0. The results suggest that an intermediate magnetic phase, which is known as the partial disordered phase, may appear even in a finite magnetic field.