Speculations on the critical behavior of reduced moment antiferromagnetic cerium compounds (invited)

Abstract

In certain trivalent cerium compounds, fast spin fluctuations associated with the proximity of the 4f level to the Fermi level completely suppress magnetic order; in others the ground state is antiferromagnetic, but the spin fluctuations show up in thermodynamic and spectroscopic properties. These effects reflect the proximity in parameter space to a zero-temperature magnetic/nonmagnetic transition. The critical behavior associated with this transition falls in the category of ’’quantum critical phenomena’’ and is expected to be quite interesting. This paper discusses the results of recent neutron scattering experiments in CeIn3 in the light of this expected behavior. Key features are nearly-mean-field behavior and strong suppression of the critical fluctuations. Comparisons will be made to the behavior of the more conventional cerium based metamagnet CeAl which we have recently determined, as well as to the behavior of other spin fluctuation magnets, such as CeAl2.