S 12 Sadovnikov, S. I. An in situ high-temperature scanning electron microscopy study of acanthite-argentite phase transformation in nanocrystalline silver sulfide powder / S. I. Sadovnikov, A. I. Gusev, A. A. Rempel // Physical Chemistry Chemical Physics. - 2015. - Vol. 17, № 32. - P20495-20501. - Библиогр.: с. 20501 (30 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ФАЗОВЫЕ ПРЕВРАЩЕНИЯ -- ПОРОШКИ -- ПОРОШКИ НАНОКРИСТАЛЛИЧЕСКИЕ Аннотация: For the first time, the α-Ag2S (acanthite)–β-Ag2S (argentite) phase transformation in nanocrystalline and coarse-crystalline powders of silver sulfide has been observed in situ by the scanning electron microscopy method in real-time. The argentite crystals are formed on the surface of acanthite particles as a result of electron-beam heating. According to the differential thermal analysis data, the transformation occurs at a temperature of ∼449–450 K, and the enthalpy of transformation is equal to ∼3.7–3.9 kJ mol−1. The presence of α-Ag2S (acanthite)–β-Ag2S (argentite) phase transformation is confirmed in situ by high-temperature X-ray diffraction data. |