2002/08/28 by Yun Song, Shiping Feng
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:10.1088/0953-8984/14/36/312
published as J. Phys. Condens. Matter 14, 8563 (2002) · 12 pages, 6 figures
openalex publication_date 2002/08/28 · arxiv created 2002/09/18 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
The Schwinger-boson mean-field theory is used to study the three-dimensional antiferromagnetic (AF) ordering and excitations in the compounds L 2 BaNiO 5 , a large family of quasi-one-dimensional mixed-spin antiferromagnets. To investigate the magnetic properties of these compounds, we introduce a three-dimensional mixed-spin AF Heisenberg model based on experimental results for the crystal structure of L 2 BaNiO 5 . This model can explain the experimental finding of coexistence of the Haldane gap and AF long-range order below the Néel temperature. Properties such as the low-lying excitations, magnetizations of Ni and rare-earth ions, Néel temperatures of different compounds, and the behaviour of the Haldane gap below the Néel temperature are investigated within this model, and the results are in good agreement with neutron scattering experiments.