Analysis of the Formation Process of Sulphur plus Gold Sensitization Specks by the Electron Diffraction Method

Abstract

Sensitization specks formed on pure silver bromide tabular and cubic grains were analysed by a selected-area electron diffraction (ED) method. The grains received a sulphur sensitization treatment at first and were then treated with tetrachloroaurate(III) solution. The ED pattern after the sulphur sensitization indicated that a crystal of Ag₂S has an epitaxy to the AgBr surface. After treatment with Au^III solution the ED pattern altered to a crystal of Ag₃AuS₂ on the tabular grains. They also had an epitaxy to AgBr. On the cubic grains, however, the Ag₂S crystal did not alter after the A^III treatment.