Optical properties of LiNbO3 : Cr crystals co-doped with germanium oxide
Por:
Camarillo E., Murrieta H., Hernandez J.M., Zoilo R., Flores M.C., Han, TPJ, Jaque F.
Publicada:
1 may 2008
Resumen:
Lithium niobate (LiNbO3) crystals doped with chromium ions show a clear green colouring reflecting the absorption profile of the dominating [Cr](Li) defect centres. A significant change in its colouration takes place when it is co-doped with other valency impurities such as Mg2+, Sc3+ and W6+, above a certain threshold concentration. This concentration singularity has been attributed to the formation of [Cr](Nb) centres coexisting with the [Cr](Li) centres. In this work, we extended the investigation on the effect of co-dopant ions in Cr:LiNbO3 to tetravalent cation such as GeO2. A singularity in the relative intensity of the (4)A(2)-> T-4(1) and (4)A(2)-> T-4(2) absorption band was observed for a concentration of similar to 1.5 mol%, compared with 4.5 mol% for Mg2+. The photoluminescence emission spectra also reveal a new emission band, at a lower energy than the [Cr](Li) centre, corresponding to this threshold concentration. A charge compensation model is proposed to explain the role
Filiaciones:
Camarillo E.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico
Instituto de Fìsica, Universidad Nacional Autònoma de Mèxico, Apartado Postal 20-364, C.P. 01000 Mexico D.F., Mexico
Murrieta H.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico
Instituto de Fìsica, Universidad Nacional Autònoma de Mèxico, Apartado Postal 20-364, C.P. 01000 Mexico D.F., Mexico
Hernandez J.M.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico
Instituto de Fìsica, Universidad Nacional Autònoma de Mèxico, Apartado Postal 20-364, C.P. 01000 Mexico D.F., Mexico
Zoilo R.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico
Instituto de Fìsica, Universidad Nacional Autònoma de Mèxico, Apartado Postal 20-364, C.P. 01000 Mexico D.F., Mexico
Flores M.C.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico
Instituto de Fìsica, Universidad Nacional Autònoma de Mèxico, Apartado Postal 20-364, C.P. 01000 Mexico D.F., Mexico
Jaque F.:
Department of Physics, University of Strathclyde, 107 Rottenrow, Glasgow G4 0NG, United Kingdom
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