A low-temperature route for the synthesis of Ag2S, Ag2Te and their solid solutions Ag2S1 −xTex(0 ≤x ≤ 1) is reported. Ag2S is prepared by the direct addition of silver nitrate solution to thiourea, while Ag2 Te is prepared by reacting silver nitrate solution with tellurium in nitric acid and subsequently reducing it with hydrazine hydrate. The solid solutions of Ag2S and Ag2Te are obtained by the addition of nitrate solutions of silver and tellurium to thiourea followed by its reduction with hydrazine hydrate. The method enables the synthesis of low-temperature crystalline phase of Ag2S1 −xTex solid solutions. The powder X-ray diffraction studies suggest that the solid solutions of compositionsx 〈 0·3 have a phase akin toα-Ag2S and those with compositionsx 〉 0·6 are similar toα-Ag2 Te. In the intermediate range of compositions (x=0·4 and 0·5), the solid solutions are found to be mixtures ofα-Ag2S andα-Ag2 Te phases which transform totally toα-Ag2S phase on prolonged annealing at about 473 K.
Volume 42 | Issue 6
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