Phase transitions in Cs5(HSO4)2(H2PO4)3 crystal

Investigation of the structure of Cs3(HSO4)2(H2PO4) single crystals

“…Therefore, to search for new compounds, we constructed phase diagrams of this system at different temperatures. As a result of our study, a new Cs 6 H(HSO 4 ) 3 (H 2 PO 4 ) 4 compound was revealed for the first time [15]. In addition, we synthesized the Cs 3 (HSO 4 ) 2 (H 2 PO 4 ) compound in the form of large single crystals; a transition to the high-conductivity state at a temperature T sp ≈ 411 K was revealed in them.…”

“…When growing its crystals with a controlled decrease in temperature, one should be restricted to a value of 313 K as the upper temperature limit and the component ratio CsHSO 4 : CsH 2 PO 4 = 1 : 1. At higher temperatures, the Cs 6 H(HSO 4 ) 3 (H 2 PO 4 ) 4 compound is crystallized from this solution [15].…”

Superprotonics—crystals with rearranging hydrogen bonds

“…At the Shubnikov Institute of Crystallography, the phase dia gram of the CsH 2 PO 4 -CsHSO 4 -H 2 O ternary system was systematically studied for the first time, based on which it became possible to synthesize and grow Cs 3 (HSO 4 ) 2 (H 2 PO 4 ) and Cs 4 (HSO 4 ) 3 (H 2 PO 4 ) crystals ( Fig. 9) [39]. Precision measurements of its complex impedance showed that the single crystal transforms to the superprotonic phase, and its con ductivity reaches 10 -2 Ω -1 cm -1 at a relatively low temperature of ~120°C.…”

Study of phase equilibria in the Rb3H(SO4)2-RbH2PO4-H2O system

“…For example, the CsHSO 4 -CsH 2 PO 4--H 2 O water-salt system was systematically investigated only recently [4]. As a result of that investigation, a new compound, Cs 6 (H 2 SO 4 ) 3 (H 2 PO 4 ) 4 , with high proton conductivity was found [5,6]. In this family of crystals, the RbHSO 4 -RbH 2 PO 4 -H 2 O system is also promising for both fundamental and applied research.…”