A Model for Correlated Metamagnets: Application to UPt$_3$ and CeRu$_2$Si$_2$

Abstract

In a model system with three S=1 pseudo-spins situated in an anisotropic mean field we compute the thermodynamic response in a self consistent manner. An adhoc uniform broadening of all energy levels of the (localized) spins due to their interaction with conduction electrons is introduced. The results with a minimal set of parameters reproduce with remarkable fidelity the properties of the strongly correlated metamagnets UPt3 and CeRu2Si2. Several key predictions are made for further experimental confirmation.

Temperature dependence of nonlinear susceptibilities in an infinite range interaction model

“…The series of compounds CeMIn 5 show a Curie law susceptibility at low temperatures as reported by Thamizhavel et al [13]. B. Shivaram [14] has noted several instances of metamagnetism in different contexts. For a review of molecular magnets see also Ref.…”

“…This closed form is not obvious from Eq. (14). By rearranging the terms for f 3/2 (b/τ ) and f 5/2 (b/τ ), they can be rewritten using a nicer recursion relation:…”