Crystal field and microwave absorption spectra in tetragonal HoBa.sub.2./sub.Cu.sub.3./sub.O.sub.x./sub.(x = 6.0, 6.3)

0351332 - FZÚ 2011 RIV US eng J - Journal Article
Kazei, Z.A. - Snegirev, V. V. - Danilova, N.P. - Goiran, M. - Nekvasil, Vladimír - Kozeeva, L. P. - Kameneva, M.Yu.
Crystal field and microwave absorption spectra in tetragonal HoBa₂Cu₃O_x(x = 6.0, 6.3).
Physical Review. B. Roč. 82, č. 13 (2010), 134444/1-134444/10. ISSN 1098-0121
R&D Projects: GA AV ČR IAA100100803
Grant - others:EuroMagtNet II(XE) 228043
Institutional research plan: CEZ:AV0Z10100521
Keywords : level splitting * crystal field * microwave * layered perovskites
Subject RIV: BM - Solid Matter Physics ; Magnetism
Impact factor: 3.772, year: 2010

The microwave resonance absorption at wavelengths 871, 406, 305, and 118 μm in tetragonal layered perovskites HoBa2Cu3Ox (x ≈ 6.0, 6.3) in pulsed magnetic fields up to 40 T has been observed. This absorption is caused by the electronic transitions between low lying levels of the Ho3+ ion in the crystal field. The positions and intensities of the tetragonal symmetry allowed absorption lines for the crystal with x = 6.0 in the magnetic field oriented along the principal tetragonal axes are adequately described in terms of the available crystal field parameters. To explain the symmetry forbidden absorption lines, it is necessary to take into account the effect of the inhomogeneous orthorhombic and monoclinic components of the crystal field as well as an effective exchange field from the ordered Cu2+ subsystem at the Ho3+ sites. The origin of the local deviations from the ideal tetragonal symmetry are ascribed to disorder in the oxygen subsystem.
Permanent Link: http://hdl.handle.net/11104/0191108