Research of new AgX crystal forms by transmission electron microscopy

✍ Scribed by Novikova, Lidia A.; Kurakin, Sergey I.

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 211 KB
• Volume: 42
• Category: Article
• ISSN: 1059-910X
• DOI: 10.1002/(sici)1097-0029(19980715)42:2<148::aid-jemt9>3.0.co;2-p

✦ Synopsis

The research of AgX (X ϭ Cl, Br) crystals grown from ammonia solution as a function of X-supersaturation, gelatin concentration, temperature, and use of growth modificators, has been enhanced by data from transmission electron microscopy. The study resulted in preparing AgBr thin films with the most developed 51006 side of rombododecahedron. The size of the crystals was 5 x 15 mm. The thickness was several µm. The new forms of AgBr and AgCl microcrystals were obtained from a high concentrated solution of the corresponding salts in NH 4 OH. These microcrystals were named ''X,'' ''Y'' crystals [AgBr] and stereostructures [AgCl] deriving from their external shapes. As a result of the variation of crystallization parameters, six various morphological types of stereostructures, distinguishable by the size of a central element in relation to external elements and a length of a binding element, were seen. Experiments on photolysis of the stereostructures at the substrate temperature 25-200 0 C were carried out in vacuum. Exposure to mercury lamp light resulted in characteristic location of large particles of photolytic silver on the stereostructure surface, depending on substrate temperature.