Anomalous Magnetization of RbFeCl₃ around 31T in Pulsed High Magnetic Fields

抄録

Magnetizations of the triangular antiferromagnets RbFeCl₃ and RbFeBr₃ are measured in pulsed high magnetic fields up to 40T at liquid ⁴He temperatures. In the case of RbFeCl₃, the magnetization is found to increase almost linearly from the zero field, and to be flattened at some critical field of 14T. Further application of magnetic fields induces an anomalous double-step magnetization around 31T. The phenomenon is similar to the one which was found in CsFeCl₃ at some higher magnetic field, but noteworthy is the existence of a fine structure in the anomalous magnetization of RbFeCl₃. The anomaly has thus far not been observed for RbFeBr₃ in the measured magnetic fields up to 85T.