2003/05/12 by Hirokazu Tsunetsugu, Yukitoshi Motome
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.68.060405
published as Phys. Rev. B 68, 060405(R) (2003) · 4 pages, 4 figures, submitted to Phys. Rev. B
arxiv created 2003/05/12 · openalex publication_date 2003/08/27 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We propose a scenario for the two phase transitions in AV2O4 (A=Zn, Mg, Cd), based on an effective spin-orbital model on the pyrochlore lattice. At high temperatures, spin correlations are strongly frustrated due to the lattice structure, and the transition observed at \ensuremath∼50K is attributed to an orbital order, supported by Jahn-Teller lattice distortion. This orbital order introduces spatial modulation of spin-exchange couplings depending on the bond direction. This partially releases the frustration and leads to a spin order observed at \ensuremath∼40K. We also study the stable spin configuration by taking account of third-neighbor exchange couplings and quantum fluctuations. The result is consistent with the experimental results.