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EPR investigations on the hole centres in CaWO 4 at T = 4.2 K
Author(s) -
Biederbick R.,
Born G.,
Hofstaetter A.,
Scharmann A.
Publication year - 1975
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.2220690106
Subject(s) - electron paramagnetic resonance , hyperfine structure , atomic orbital , tetrahedron , tensor (intrinsic definition) , physics , crystallography , condensed matter physics , atomic physics , chemistry , nuclear magnetic resonance , electron , quantum mechanics , geometry , mathematics
EPR investigations at T = 4.2 K show the principal g ‐values of the radiation induced hole centres in CaWO 4 being different from those obtained at temperatures ≧ 78 K, whereas the principal directions of the g ‐tensor remain nearly unchanged. The g ‐tensor at T = 4.2 K is quite well explained by a model in which the hole is assumed in an oxygen P π ‐orbital, including some admixtures from other orbitals of the WO 4 tetrahedron. In this model, combined with a weak bonding between two neighboured WO 4 tetrahedra, the observed hyperfine interaction of the hole with two inequivalent W 183 nuclei can be understood too. The transition to the results at higher temperatures is possible by a faster exchange of the hole between the two WO 4 complexes.