Publication
Title
High-frequency electron paramagnetic resonance of the hole-trapped antisite bismuth center in photorefractive bismuth sillenite crystals
Author
Abstract
The hole-trapped antisite bismuth center has been directly observed by W-band (94 GHz) electron paramagnetic resonance (EPR) in the series of sillenite crystals, Bi12MO20 (M=Ge,Si,Ti, denoted as BMO), either nondoped or doped with transition ions (Cr, Cu, Ru, Ce). Blue light illumination influences the EPR intensity in most crystals, while in nondoped Bi12GeO20 and Bi12SiO20 the signals only appear upon illumination. The spectra can be attributed to a single species and no anisotropy could be detected eliminating any significant deviation from tetrahedral symmetry due to a perturbing defect in the near neighborhood or to static lattice distortion. The large and isotropic hyperfine parameter, in good agreement with previous optically detected magnetic-resonance measurements [Phys. Rev. B 47, 5638 (1993)], reveals that only ~25% of the hole is in the Bi 6s1 orbital, by delocalization mainly to the neighboring oxygen ions, with extremely small spin densities on the surrounding Bi3+ lattice ions as derived from the EPR linewidths. The parameter variations between the three crystalline hosts are very small, showing a near-identical degree of delocalization of the trapped hole.
Language
English
Source (journal)
Physical review : B : condensed matter and materials physics. - Lancaster, Pa, 1998 - 2015
Publication
Lancaster, Pa : 2009
ISSN
1098-0121 [print]
1550-235X [online]
Volume/pages
79(2009), p. 033107,1-033107,4
ISI
000262978200007
Full text (Publisher's DOI)
Full text (open access)
UAntwerpen
Faculty/Department
Research group
Publication type
Subject
Affiliation
Publications with a UAntwerp address
External links
Web of Science
Record
Identification
Creation 03.04.2009
Last edited 13.11.2017
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