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arXiv · 0804.2308

Mean-field model for magnetic orders in NpTGa5 with T=Co, Ni or Rh

Annamaria Kiss·Yoshio Kuramoto
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Abstract

Characteristics of magnetic transitions in NpTGa$_5$ with T=Co, Ni, Rh are explained in a unified way with use of a crystalline electric field (CEF) model of localized 5$f^4$ electrons. The model takes a CEF doublet and a singlet as local states, and includes dipolar and quadrupolar intersite interactions in the mean-field theory. Diverse ordering phenomena are derived depending on the magnitude of interaction parameters, which qualitatively reproduce the experimentally observed magnetic behaviors in NpTGa$_5$. The quadrupole degrees of freedom are essential to the diverse magnetic orders. It is argued that NpRhGa$_5$ is close to a multicritical point where quadrupoles and dipoles with different directions are competing to order.

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Annamaria Kiss, Yoshio Kuramoto. 2008-04-15. Mean-field model for magnetic orders in NpTGa5 with T=Co, Ni or Rh. https://doi.org/10.1143/jpsj.75.034709

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