# Neutron scattering study of commensurate magnetic ordering in single crystal CeSb$_2$

## TL;DR

This study investigates the magnetic phase transitions and ordering in CeSb$_2$ using magnetization measurements and neutron scattering, revealing multiple metamagnetic transitions and antiferromagnetic ground state with specific wave vectors.

## Contribution

It provides detailed neutron scattering evidence of the commensurate antiferromagnetic order and characterizes the multiple magnetic transitions in CeSb$_2$.

## Key findings

- Identification of three metamagnetic transitions at low temperatures.
- Confirmation of antiferromagnetic order with specific wave vectors.
- Observation of a first-order transition at the Nél temperature.

## Abstract

Temperature and field-dependent magnetization $M(H,T)$ measurements and neutron scattering study of a single crystal CeSb$_2$ are presented. Several anomalies in the magnetization curves have been confirmed at low magnetic field, i.e., 15.6 K, 12 K, and 9.8 K. These three transitions are all metamagnetic transitions (MMT), which shift to lower temperatures as the magnetic field increases. The anomaly at 15.6 K has been suggested as paramagnetic (PM) to ferromagnetic (FM) phase transition. The anomaly located at around 12 K is antiferromagnetic-like transition, and this turning point will clearly split into two when the magnetic field $H\geq0.2$ T. Neutron scattering study reveals that the low temperature ground state of CeSb$_2$ orders antiferromagnetically with commensurate propagation wave vectors $\textbf{k}=(-1,\pm1/6,0)$ and $\textbf{k}=(\pm1/6,-1,0)$, with N\'eel temperature $T_N\sim9.8$ K. This transition is of first-order, as shown in the hysteresis loop observed by the field cooled cooling (FCC) and field cooled warming (FCW) processes.