Long Range Magnetic Order on the Kondo Lattice ---SDW in Ce(Ru_1-xRh_x)₂Si₂ as Studied by Neutron Diffraction

Abstract

We report results of neutron-diffraction experiments which have been carried out to study the long range magnetic order developing on the Kondo lattice of the pseudo-binary-alloy system Ce(Ru_1-xRh_x)₂Si₂ with x around 0.15. The ground-state structure of the ordered phase has a sinusoidal modulation of the moment, that is, a modulation with an incommensurable wave number and a uniaxial polarization. We assign this phase to the same category of magnetism as that of the spin-density wave in metals. Several characteristic quantities of this ordering such as the order parameter, the wave number, the amplitude and the anisotropy of the polarization and the anomaly in the lattice-constant are analyzed and discussed in terms of either the s-d model or the hybridized f-band model of Kondo effect.