# Magnetic field induced antiferromagnetic tricritical points in Ce$_2 $Sb and Ce$_2 $Bi

## TL;DR

This study investigates how magnetic fields induce tricritical points in Ce$_2$Sb and Ce$_2$Bi, revealing the nature of phase transitions and the effects of chemical pressure on these magnetic materials.

## Contribution

It provides the first detailed analysis of field-induced tricritical points in Ce$_2$Sb and Ce$_2$Bi, linking chemical substitution to phase transition behavior.

## Key findings

- Metamagnetic transitions observed at low temperatures.
- Transition changes from second-order to first-order, indicating tricritical points.
- Replacing Bi with Sb suppresses the TCP to lower temperatures.

## Abstract

We present a detailed investigation of the physical properties of Ce$_2 $Sb and Ce$_2 $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 Ce$_2$Sb may suppress the TCP to lower temperatures, potentially to zero temperature at a quantum tricritical point.