Publication
Title
Revealing the $Cu^{2+}$ ions localization at low symmetry Bi sites in photorefractive $Bi_{12}GeO_{20}$ crystals doped with Cu and V by high frequency EPR
Author
Abstract
 The sites of incorporation of Cu2+ impurity ions in Bi12GeO20 single crystals co-doped with copper and vanadium have been investigated by electron paramagnetic resonance (EPR). While the X-band EPR spectra consist of a simple broad (Delta B similar to 50 mT) line with anisotropic lineshape, the W-band EPR spectra exhibit well resolved, strongly anisotropic lines, due to transitions within the 3d(9)-D-2 ground manifold of the Cu2+ ions. The most intense group of lines, attributed to the dominant Cu2+(I) center, displays a characteristic four components hyperfine structure for magnetic field orientations close to a < 110 > direction. The g and A tensor main axes are very close to one of the 12 possible sets of orthogonal < 1-10 >, < 00-1 > and < 110 > crystal directions. Several less intense lines, with unresolved hyperfine structure and similar symmetry properties, mostly overlapped by the Cu2+(I) spectrum, were attributed to Cu-2 (+)(II) centers. The two paramagnetic centers are identified as substitutional Cu2+ ions at Bi3+ sites with low C-1 symmetry, very likely resulting from different configurations of neighboring charge compensating defects. (C) 2015 Elsevier Inc. All rights reserved.
Language
English
Source (journal)
Journal of magnetic resonance. - New York, N.Y.
Publication
New York, N.Y. : 2015
ISSN
1090-7807
Volume/pages
259(2015), p. 87-94
ISI
000363358800011
Full text (Publisher's DOI)
Full text (open access)
 The author-created version that incorporates referee comments and is the accepted for publication version Available from 01.10.2017
Full text (publisher's version - intranet only)
UAntwerpen
 Faculty/Department Research group Publication type Subject Affiliation Publications with a UAntwerp address