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Optical Properties of Ni + Centres in CaF 2 :Ni and SrF 2 :Ni
Author(s) -
Alonso P. J.,
González J. Casas,
Den Hartog H. W.,
Alcalá R.
Publication year - 1980
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.2221000241
Subject(s) - irradiation , electron paramagnetic resonance , materials science , absorption (acoustics) , cube (algebra) , ion , nickel , absorption band , analytical chemistry (journal) , crystallography , nuclear magnetic resonance , chemistry , optics , metallurgy , physics , composite material , mathematics , organic chemistry , combinatorics , chromatography , nuclear physics
The optical properties of X‐irradiated CaF 2 :Ni and SrF 2 :Ni are studied. An absorption band at 255 nm in CaF 2 and 270 nm in SrF 2 is created by X‐irradiation. It is concluded from optical bleaching experiments in low‐temperature X‐irradiated samples that those absorption bands are due to Ni + ions. Optical dichroism experiments indicate that these Ni + centres are oriented along the <100> directions. A comparison with previous EPR experiments of X‐irradiated CaF 2 :Ni indicates that the centres responsible for the 255 nm band in CaF 2 :Ni and the 270 nm band in SrF 2 :Ni are Ni + ions displaced from the centre of the cube of fluorines toward one of the faces of that cube.