Optical vibronic spectra of aggregates in Eu2+ -doped KCl and KBr crystals
R. Pérez-Salas, T. M. Piters, R. Aceves, R. Rodríguez-Mijangos, and M. Barboza-Flores
Centro de Investigación en Física, Universidad de Sonora, Apartado Postal 5-088, Hermosillo, Sonora 83190, México.
Recibido el 3 de abril de 2002. ]]> Aceptado el 6 de noviembre de 2002.
Abstract
The vibronic structure on the optical absorption, emission, and excitation spectra of aggregates in Eu2+-doped KCl and KBr crystals has been obtained. The crystals were annealed at 435K. During the aggregation process, four groups of narrow bands were found in KCl:Eu2+ and two, in KBr:Eu2+, which were considered as the signature of different Eu2+-ion aggregated phases. The vibration frequency for each group is very similar.
Keywords: Luminiscence in solids; alkali halides with europium.
Resumen
La estructura vibrónica de los espectros de emisión, absorción y excitación de cristales de KCl y KBr impurificados con europio divalente, se ha obtenido experimentalmente. Los cristales fueron envejecidos a 435K. Durante el proceso de agregación, se encontraron cuatro grupos KCl: Eu+2 y dos en KBr: Eu+2, las cuales se consideraron como la firma de diferentes fases agregadas de iones Eu+2. La frecuencia de vibración para cada grupo es muy similar.
Descriptores: Luminiscencia en sólidos; halogenuros alcalinos con europio.
]]> PACS: 78.55.Fv
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Acknowledgements
We acknowledge the technical assistance of Professor H. Riveros and Mr. R. Guerrero (IFUNAM) for growing the crystals. This work is supported in part by CONACYT (México, Grant No. D1520-E9201, Beca No. 84683) (México), DGICSA-SEP (México), FOMES (Universidad de Sonora, México), and the Third World Academy of Sciences (Italy). Dr. T. M. Piters is grateful to CONACYT for a Cátedra Patrimonial de Excelencia Nivel II Grant and to ANUIES (México) for the funding provided via the SUPERA Program.
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