Differential Thermal Analysis Studies on Ag 2 CO 3
1971; NRC Research Press; Volume: 49; Issue: 24 Linguagem: Inglês
10.1139/v71-665
ISSN1480-3291
AutoresG. D. Nagy, J. B. Vergette, J. P. Connolly,
Tópico(s)Energetic Materials and Combustion
ResumoThe decomposition and phase transitions that occur during the heating and cooling of Ag 2 CO 3 were studied by differential thermal analysis at heating rates of 7 to 14° per min. In helium, the Ag 2 CO 3 was partially decomposed evolving CO 2 (7–35% depending upon the method of preparation) giving rise to peaks at 190 to 200°; at 350 to 400°, two endothermic peaks were observed at which CO 2 and O 2 were given off simultaneously, leaving silver metal. In CO 2 the initial partial decomposition gave rise to a peak at about 265°. The partially decomposed Ag 2 CO 3 (Ag 2 O•nCO 2 , where n is less than one) gave the same X-ray diffraction pattern as Ag 2 O, which slowly converted to that for Ag 2 CO 3 if left exposed to air or CO 2 . The Ag 2 O•nCO 2 undergoes two distinct "reversible" phase transitions at 180 and 197° on subsequent reheatings. The Ag 2 O•nCO 2 behaves like a clathrate-type of structure in which CO 2 can be entrapped in the Ag 2 O lattice.
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