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Small‐Angle X‐ray Scattering Study on Growth of AgCl Crystallites in Photochromic Glasses
Author(s) -
Takatohi U. E.,
Bittencourt D. R. S.,
Watanabe S.
Publication year - 1997
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889897001337
Subject(s) - small angle x ray scattering , absorbance , crystallite , materials science , scattering , analytical chemistry (journal) , x ray , doping , crystallography , optics , chemistry , organic chemistry , chromatography , physics , optoelectronics
Reversible changes in the optical properties of photochromic glasses are observed owing to the presence of small silver halide crystals inside the glassy matrix. These crystals grow during the glass heat‐treatment processing. Samples with molar composition of 40SiO 2 .10Al 2 O 3 .16.1K 2 0.33.9B 2 O 3 , doped with AgCl and CuO, were produced and submitted to different heat treatments: (i) for 0.5 h at temperatures from 753 to 893 K and (ii) at 873 K for periods of time from 0.25 to 1.25 h. Small‐angle X‐ray scattering (SAXS) was used to characterize the samples. The samples heat treated between 843 and 893 K presented an increasing growth rate of the Guinier radius ( R g ). Samples heat treated at a fixed temperature of 873 K and different time t showed a law R g 3 = kt + c . Variations in the optical absorbance at 280 nm and the additional absorbance spectra of samples exposed to light showed correlation with the SAXS results.