Affiliation:
1. Shubnikov Institute of Crystallography of Federal Scientific Research Centre “Crystallography and Photonics of Russian Academy of Sciences, 119333 Moscow, Russia
Abstract
A series of solid acid compounds, representing the large family MmHn(AO4)(m + n)/2·yH2O (where M = K, Rb, Cs, NH4; AO4 = SO4, SeO4, HPO4, HAsO4), is characterized by high values of own proton conductivity, which arises as a result of a phase transition through the formation of a dynamically disordered hydrogen bond network. Such superprotonic phase transitions are observed, however, not for all compounds of the family and Rb3H(SO4)2 is one of them. The occurrence of superprotonic phase transitions has been experimentally demonstrated in the (KxRb1−x)3H(SO4)2 solid solutions through cation substitution. The high-temperature phases are unstable towards decomposition reaction, and their temperature range of existence is about 1–7 °C. The implementation of superprotonic transitions is discussed in terms of hydrogen bond lengths.
Subject
Inorganic Chemistry,Condensed Matter Physics,General Materials Science,General Chemical Engineering