Sublattice Magnetization and Néel Temperature of a Tetragonal Antiferromagnet

• Published in: Physica status solidi. B. Basic research Vol. 203; no. 2; pp. 517 - 520
• Main Authors: Du, A., Li, G. M., Wei, G. Z.
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.10.1997; WILEY‐VCH Verlag; Wiley
• Subjects: Classical spin models; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Domain effects, magnetization curves, and hysteresis; Exact sciences and technology; General theory and models of magnetic ordering; Magnetic properties; Magnetic properties and materials; Magnetization curves, hysteresis, Barkhausen and related effects; Magnetization curves, magnetization reversal, hysteresis, barkhausen and related effects; Physics; Properties of type I and type II superconductors; Superconductivity; Magnetization; Tetragonal lattices; Layered crystals; Antiferromagnetic materials; Theoretical study; Heisenberg model; XY model; Green function; Anisotropy; Sublattices; High-Tc superconductors; Neel temperature; Spin wave approximation
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/1521-3951(199710)203:2<517::AID-PSSB517>3.0.CO;2-S

By means of spin‐wave theory and spin Green function theory, we calculate the sublattice magnetization and Néel temperature of a layered Heisenberg antiferromagnet, in which two nearest‐neighbour layers are grouped in a bilayer and two nearest‐neighbour bilayers are coupled antiferromagnetically. We find that small XY anisotropy has significant influence on the Néel temperature, but has little influence on the sublattice magnetization at zero temperature and the ground state energy. The sublattice magnetization and Néel temperature calculated for YBa2Cu3O6+x (x = 0.15) are in good agreement with the experimental values. For small interlayer coupling and small XY anisotropy, the Néel temperature can be expressed in an asymptotic form.