Neutron scattering study of commensurate magnetic ordering in single crystal CeSb₂

Temperature and field-dependent magnetizationM(T,H ) measurements and neutron scattering study of a single crystal CeSb₂are presented. Several anomalies in magnetization curves have been confirmed, i.e., at 15.6 K, 12 K, and 9.8 K, respectively. These three transitions are all metamagnetic transitions, which shift to lower temperatures as the magnetic field increases. In contrast to the previous studies that the anomaly at 15.6 K has been suggested as paramagnetic to ferromagnetic phase transition, in our measurement no hysteresis loop around zero field with eitherH∥corH ⊥ chas been observed. The anomaly located at around 12 K is antiferromagnetic-like transition, and this turning point will clearly split into two when the magnetic fieldH⩾ 2 kOe. A neutron scattering study reveals that the low temperature ground state of CeSb₂orders magnetically with commensurate propagation wave vectorsk= (-1, ±1/6, 0) andk= (±1/6, -1, 0), with phase transition temperatureT_C∼ 9.8 K.