2008/06/06 by M. L. Plumer · 18 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Anisotropy #Antiferromagnetism #Condensed matter physics #Magnetic and transport properties of perovskites and related materials #Multiferroics and related materials #Phase (matter) #Phase diagram #Physics #Quantum mechanics #cond-mat.stat-mech
paper · pdf · doi:10.1103/physrevb.78.094402
published in Physical Review B 78(9) (American Physical Society) · 20 pages, 2 figures
arxiv created 2008/06/06 · openalex publication_date 2008/09/04 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
A nonlocal Landau-type free-energy functional of the spin density is developed to model the large variety of magnetic states, which occur in the magnetic-field--temperature phase diagram of magnetoelectric CuFeO2. Competition among long-range quadratic exchange, biquadratic antisymmetric exchange, and trigonal anisotropy terms, consistent with the high-temperature rhombohedral R3m crystal symmetry, are shown to all play important roles in stabilizing the unusual combination of commensurate and incommensurate spin structures in this highly frustrated triangular antiferromagnet. It is argued that strong magnetoelastic coupling is largely responsible for the nonlocal nature of the free energy. A key feature of the analysis is that an electric polarization is induced by a canting of the noncollinear incommensurate spin structure. Application of the model to ordered spin states in the triangular antiferromagnets MnBr2 and NaFeO2 is also discussed.