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A Model for the Schottky Anomaly in Metallic $Nd_{2-y}Ce_{y}CuO_{4}$

R. E. Lagos·A. C. M. Stein-Barana·G. G. Cabrera
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Abstract

We present a simple model for the doped compound $Nd_{2-y}Ce_{y}CuO_{4}$, in order to explain some recent experimental results on the latter. Within a Hartree-Fock context, we start from an impurity Anderson-like model and consider the magnetic splitting of the $Nd$-$4f$ ground state Kramers doublet due to exchange interactions with the ordered $Cu$ moments. Our results are in very good agreement with the experimental data, yielding a Schottky anomaly peak for the specific heat that reduces its amplitude, broadens and shifts to lower temperatures, upon $Ce$ doping. For overdoped compounds at low temperatures, the specific heat behaves linearly and the magnetic susceptibility is constant. A smooth transition from this Fermi liquid like behavior ocurrs as temperature is increased and at high temperatures the susceptibility exhibits a Curie-like behavior. Finally, we discuss some improvements our model is amenable to incorporate.

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R. E. Lagos, A. C. M. Stein-Barana, G. G. Cabrera. 1998-10-12. A Model for the Schottky Anomaly in Metallic $Nd_{2-y}Ce_{y}CuO_{4}$. https://doi.org/10.1016/s0921-4534(98)00576-0

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