Magnetic structure of Cd-doped CeIrIn${}_5$

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)$\hat{I}{¼}_B$ 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.

6 pages, 5 figures. Accepted for publication in Phys. Rev. B