Magnetic structure of Cd-doped CeIrIn$_5$

TL;DR

This study reveals the magnetic structure of Cd-doped CeIrIn$_5$, showing a commensurate antiferromagnetic order with moments aligned along the c axis, differing from related compounds.

Contribution

First determination of the magnetic structure of Cd-doped CeIrIn$_5$ using neutron scattering, highlighting a unique commensurate antiferromagnetic order.

Findings

Magnetic intensity observed only at $Q_{AF} = (1/2,1/2,1/2)$

Staggered magnetic moment of 0.47 μ_B on Ce ions

Magnetic moments aligned along the c axis

Abstract

We report the magnetic structure of nominally 10% Cd-doped CeIrIn$_5$, CeIr(In$_{0.9}$Cd$_{0.1}$)$_5$, determined by elastic neutron scattering. Magnetic intensity was observed only at the ordering wave vector $Q_{AF} = (1/2,1/2,1/2)$, commensurate with the crystal lattice. A staggered moment of 0.47(3)$\mu_B$ at 1.8 K resides on the Ce ion. The magnetic moments are found to be aligned along the crystallographic $c$ axis. This is further confirmed by magnetic susceptibility data, which suggest the $c$ axis to be the easy magnetic axis. The determined magnetic structure is strikingly different from the incommensurate antiferromagnetic ordering of the closely related compound CeRhIn$_5$, in which the magnetic moments are antiferromagnetically aligned within the tetragonal basal plane.