Magnetic structure of Cd-doped CeIrIn$_5$

Abstract

We report the magnetic structure of nominally 10% Cd-doped CeIrIn5, CeIr(In0.9Cd0.1)5, determined by elastic neutron scattering. Magnetic intensity was observed only at the ordering wave vector QAF = (1/2, 1/2, 1/2), commensurate with the crystal lattice. A staggered moment of 0.47(3)µB 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 CeRhIn5, in which the magnetic moments are antiferromagnetically aligned within the tetragonal basal plane.