Premium
Inelastic light scattering studies of overdoped Y 1– x Ca x Ba 2 Cu 3 O 7– δ thin film
Author(s) -
Lin J. H.,
Weng S. M.,
Liu H. L.,
Chung P. C.,
Lin J.Y.
Publication year - 2007
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.200777110
Subject(s) - superexchange , magnon , excitation , phonon , condensed matter physics , raman spectroscopy , analytical chemistry (journal) , raman scattering , energy (signal processing) , chemistry , physics , ferromagnetism , optics , chromatography , quantum mechanics
The vibrational and magnetic Raman excitation spectra were examined in overdoped Y 1–x Ca x Ba 2 Cu 3 O 7–δ thin films. Below T c , certain phonons in undoped YBa 2 Cu 3 O 7–δ (YBCO) show strong self‐energy effects, which gradually vanish with increasing Ca concentration into the overdoped regime. The observed B 1g symmetry two‐magnon excitation peak near 2900 cm –1 in YBCO is significantly broadened, weakened, and shifts to the lower frequency with increasing Ca content, indicating the effective value of magnetic superexchange energy decreases and that the life time of the magnons becomes shorter with increasing hole concentrations. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)