2003/10/31 by Takashi Hotta · 2 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Rare-earth and actinide compounds #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.70.054405
published as Phys. Rev. B 70, 054405 (2004). · 10 pages. 8 figures embedded in the text. To appear in Phys. Rev. B
arxiv created 2004/06/11 · openalex publication_date 2004/08/09 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Key role of orbital degree of freedom to understand the magnetic structure of uranium compounds is discussed from a microscopic viewpoint by focusing on typical examples such as UMGa5 (M=Ni and Pt) and the mother compound UGa3. By analyzing an orbital degenerate Hubbard model constructed from the j\penalty1000-\hskip0ptj coupling scheme in the cubic system, we obtain the phase diagram including several kinds of magnetic states. Especially, in the parameter region corresponding to actual uranium compounds, the phase diagram suggests successive transitions among paramagnetic, magnetic metallic, and insulating N'eel states, consistent with the experimental results for AuCu3-type uranium compounds. Furthermore, taking account of tetragonal effects such as level splitting and reduction of hopping amplitude along the z axis, an orbital-based scenario is proposed to understand the change in the magnetic structure from G- to A-type antiferromagnetic phases, experimentally observed in UNiGa5 and UPtGa5.