Optical studies of divalent europium doped mixed KCl-KBr crystals
Por:
Aguilar M. A., Benitez F., Verdiguel G. H., Aguilar S. G., Camarillo E., Hernandez A. J., Cabrera B. E., Murrieta S. H.
Publicada:
1 ene 1998
Resumen:
A study about the aggregation-precipitation processes of divalent europium ions in mixed potassium halides (Cl/Br) has been carried out. Quenched samples lead to a single emission band at 418 nm, which compared with the emission observed in the corresponding europium doped non-mixed alkali halide crystals, appears perturbed by the presence of Cl or Br ions. This band has been ascribed to free europium-vacancy complexes. The annealing at 353 K produces an emission band composed of several contributions: (1) free dipoles, (2) an emission that might be attributed to a Suzuki type mixed phase containing chloride as well as bromide ions and (3) a band due to a metastable mixed phase peaking at around 450 nm. On the other hand, the annealing at 473 K induces metastable phases of the dihalide type emitting at 430, 448 and 474 nm. The intensity of these bands changes as a function of the content of halogen ions.
Filiaciones:
Institute de Fisica, Univ. Nac. Auton. de México, Apdo. Postal 20-364, México, D.F., Mexico
Inst. de Invest. en Materielles, Univ. Nac. Auton. de México, Apdo. Postal 70-360, México, D.F., Mexico
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