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Titolo:
CHARACTERIZATION OF HIGH-EFFICIENCY HYPERSENSITIZATION OF AGBR EMULSION BY GOLD(I) THIOCYANATE SOLUTION
Autore:
KAWASAKI M; OKU Y;
Indirizzi:
KYOTO UNIV,DIV MOLEC ENGN KYOTO 60601 JAPAN
Titolo Testata:
Journal of Photographic Science
fascicolo: 4, volume: 43, anno: 1995,
pagine: 122 - 130
SICI:
0022-3638(1995)43:4<122:COHHOA>2.0.ZU;2-Z
Fonte:
ISI
Lingua:
ENG
Soggetto:
MINIMUM SIZE; LATENT IMAGE; MULTIFLASH RESPONSES; SENSITIZED EMULSIONS; SILVER; LATENSIFICATION; SUBIMAGE; CENTERS; MECHANISM; ATOM;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
25
Recensione:
Indirizzi per estratti:
Citazione:
M. Kawasaki e Y. Oku, "CHARACTERIZATION OF HIGH-EFFICIENCY HYPERSENSITIZATION OF AGBR EMULSION BY GOLD(I) THIOCYANATE SOLUTION", Journal of Photographic Science, 43(4), 1995, pp. 122-130

Abstract

Pre-exposure treatments of primitive and S-sensitized AgBr emulsion coatings with a gold(I) thiocyanate solution yield, under certain experimental conditions, a large sensitizing effect that cannot be gained by post-exposure subimage latensification. The most critical condition for this high-efficiency Au-hypersensitization is inclusion of a washing step following the gold-bath treatment. The hypersensitizing centrecan be identified with small Au clusters on the grain surface, deposited probably through washing-assisted decomplexation of gold(I) thiocyanates followed by disproportionation of Au+ ions. These Au clusters may grow to a developable latent image during exposure, thus allowing an unique mode of latent image formation that involves no unstable intermediates. As a result, the low intensity failure is eliminated and, if the development condition is strengthened enough, only a single growth event may become sufficient to make a grain developable. However, the Au-hypersensitization does not significantly improve the quantum efficiency of each individual growth step in latent image formation. It is estimated that this efficiency remains at similar to 10% or below for the S-sensitized and primitive coatings even after the Au-hypersensitization. In contrast, the corresponding quantum efficiency in conventional S + Au-sensitized emulsions may exceed 40%, indicating another unique function of gold associated with S + Au-sensitization centres.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 25/01/20 alle ore 19:18:41