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 - Článek v odborném periodiku
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
Grant CEP: GA AV ČR IAA100100803
Grant ostatní: EuroMagtNet II(XE) 228043
Výzkumný záměr: CEZ:AV0Z10100521
Klíčová slova: level splitting * crystal field * microwave * layered perovskites
Kód oboru RIV: BM - Fyzika pevných látek a magnetismus
Impakt faktor: 3.772, rok: 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.
Trvalý link: http://hdl.handle.net/11104/0191108