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Orbital-based Scenario for Magnetic Structure of Neptunium Compounds

Hiroaki Onishi·Takashi Hotta
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Abstract

In order to understand a crucial role of orbital degree of freedom in the magnetic structure of recently synthesized neptunium compounds NpTGa_5 (T=Fe, Co, and Ni), we propose to discuss the magnetic phase of an effective two-orbital model, which has been constructed based on a j-j coupling scheme to explain the magnetic structure of uranium compounds UTGa_5. By analyzing the model with the use of numerical technique such as exact diagonalization, we obtain the phase diagram including several kinds of magnetic states. An orbital-based scenario is discussed to understand the change in the magnetic structure among C-, A-, and G-type antiferromagnetic phases, experimentally observed in NpFeGa_5, NpCoGa_5, and NpNiGa_5.

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Hiroaki Onishi, Takashi Hotta. 2004-11-04. Orbital-based Scenario for Magnetic Structure of Neptunium Compounds. https://doi.org/10.1088/1367-2630%2F6%2F1%2F193

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