Low temperature magnetic structure of CeRhIn$_5$ by neutron diffraction on absorption-optimized samples

TL;DR

This study clarifies the magnetic structure of CeRhIn$_5$ at low temperatures, confirming its helical nature and measuring the ordered magnetic moment using optimized neutron diffraction techniques.

Contribution

The paper provides the first precise measurement of the magnetic moment and confirms the helical magnetic structure of CeRhIn$_5$ using absorption-optimized neutron diffraction and polarimetry.

Findings

Ordered magnetic moment of 0.54(2) μ_B

Confirmation of helical magnetic structure

Identification of a single chiral domain

Abstract

Two aspects of the ambient pressure magnetic structure of heavy fermion material CeRhIn$_5$ have remained under some debate since its discovery: whether the structure is indeed an incommensurate helix or a spin density wave, and what is the precise magnitude of the ordered magnetic moment. By using a single crystal sample optimized for hot neutrons to minimize neutron absorption by Rh and In, here we report an ordered moment of $m=0.54(2)~\mu_B$. In addition, by using spherical neutron polarimetry measurements on a similar single crystal sample, we have confirmed the helical nature of the magnetic structure, and identified a single chiral domain.