Magnetic field induced antiferromagnetic tricritical points in Ce2 Sb and Ce2 Bi
Abstract
We present a detailed investigation of the physical properties of Ce2 Sb and Ce2 Bi single crystals, which undergo antiferromagnetic transitions at around 8.2 and 10 K respectively. When magnetic fields are applied parallel to the c axis, metamagnetic transitions are observed at low temperatures, corresponding to a magnetic field-induced phase transition. It is found that the field-induced transition changes from second-order at higher temperatures, to first-order at low temperatures, suggesting the existence of tricritical points (TCPs) in both compounds. Since replacing Bi with Sb suppresses the TCP to lower temperatures and corresponds to a positive chemical pressure, these results suggest that applying pressure to Ce2Sb may suppress the TCP to lower temperatures, potentially to zero temperature at a quantum tricritical point.