Magnetization study on the antiferro-quadrupolar ordering in PrPb₃

Quadrupolar ordering in the cubic compound PrPb₃ has been studied by DC magnetization measurements at temperatures down to T ∼ 50 mK in fields (H∥ [1 0 0]) up to 8 T. The quadrupolar ordering temperature T_Q(H), below which the magnetic susceptibility is enhanced, is found to increase in H from 0.4 K at H = 0 to 0.6 K at H = 5 T. On cooling below T_Q(H), sharp metamagnetic transitions develop in the magnetization process at around 7 T. The resulting H-T phase diagram can be explained by incorporating magnetic interactions between the field-induced antiferromagnetic moments in the O₂⁰ type antiferro-quadrupolar phase.