The effect of magnetization direction on excitations in a gamma 5 ground state system

• Published in: Solid state communications Vol. 70; no. 2; pp. 179 - 183
• Main Authors: Wentworth, C.D., Deutz, A.F.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.04.1989; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; General theory and models of magnetic ordering; Magnetic properties and materials; Materials science; Metals, semimetals and alloys; Other topics in magnetic properties and materials; Physics; Quantized spin models; Specific materials; Magnetization direction; Intermetallic compound; Exchange interaction; Laves phase; Theoretical study; Lanthanide Alloys; Crystal field; Green function; Binary alloy; Collective excitation; Magnetic properties
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/0038-1098(89)90970-8

Collective magnetic excitations are discussed for a J = 6 system of localized spins in a cubic crystal field with Γ 5 ground state interacting through isotropic Heisenberg exchange. It is found that the choice of zero-field magnetization direction is important for obtaining physically reasonable dispersion curves. The direction must be the easy-axis corresponding to the crystal field parameters used. Examples of dispersion curves in the ferromagnetically ordered phase with model parameters corresponding to TmAl 2 are given. The presence of an additional interaction in TmAl 2 is inferred.