TY - JOUR
T1 - Crystal structure, conductivity, and phase stability of Cs3(H1.5PO4)2 under controlled humidity
AU - Sanghvi, Sheel
AU - Haile, Sossina M.
N1 - Funding Information:
Financial support has been provided by National Science Foundation ( DMR 1807234 ). PXRD experiments made use of the Jerome B. Cohen X-ray Diffraction Facility supported by the MRSEC program of the National Science Foundation ( DMR-1720139 ) at the Materials Research Center of Northwestern University and the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource ( NSF ECCS-1542205 ). SCXRD experiments made use of the Integrated Molecular Structure Education and Research Center (IMSERC) at Northwestern University, which has received support the State of Illinois and International Institute for Nanotechnology (IIN). The authors thank Charlotte Stern for single crystal data collection.
Funding Information:
Financial support has been provided by National Science Foundation (DMR 1807234). PXRD experiments made use of the Jerome B. Cohen X-ray Diffraction Facility supported by the MRSEC program of the National Science Foundation (DMR-1720139) at the Materials Research Center of Northwestern University and the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205). SCXRD experiments made use of the Integrated Molecular Structure Education and Research Center (IMSERC) at Northwestern University, which has received support the State of Illinois and International Institute for Nanotechnology (IIN). The authors thank Charlotte Stern for single crystal data collection.
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2020/6
Y1 - 2020/6
N2 - Upon heating, a number of solid acids of structure type M3H(XO4)2 (M = NH4, K, Rb, Cs; X = S, Se) transform from a low conductivity monoclinic phase into a high conductivity (superprotonic) phase. Here, a new member of this material class, Cs3(H1.5PO4)2, is studied using a combination of single crystal X-ray diffraction, in-situ powder diffraction, thermogravimetric analysis, and A.C. impedance spectroscopy. The room temperature crystal structure of Cs3(H1.5PO4)2 was solved in the C2/m space group and found to be essentially isostructural to Cs3H(SeO4)2. On heating, no transition to a superprotonic phase was observed. Instead, Cs3(H1.5PO4)2 exsolves a small quantity of a CsH2PO4-like cubic phase at an onset temperature of ~192 °C prior to decomposition. The absence of a superprotonic phase transition is discussed in the context of other M3H(XO4)2 solid acids and the crystal-chemical features that define this class of materials.
AB - Upon heating, a number of solid acids of structure type M3H(XO4)2 (M = NH4, K, Rb, Cs; X = S, Se) transform from a low conductivity monoclinic phase into a high conductivity (superprotonic) phase. Here, a new member of this material class, Cs3(H1.5PO4)2, is studied using a combination of single crystal X-ray diffraction, in-situ powder diffraction, thermogravimetric analysis, and A.C. impedance spectroscopy. The room temperature crystal structure of Cs3(H1.5PO4)2 was solved in the C2/m space group and found to be essentially isostructural to Cs3H(SeO4)2. On heating, no transition to a superprotonic phase was observed. Instead, Cs3(H1.5PO4)2 exsolves a small quantity of a CsH2PO4-like cubic phase at an onset temperature of ~192 °C prior to decomposition. The absence of a superprotonic phase transition is discussed in the context of other M3H(XO4)2 solid acids and the crystal-chemical features that define this class of materials.
KW - Cs(HPO)
KW - CsH(SeO)
KW - MH(XO)
KW - Proton conductor
KW - Solid acid
KW - Superprotonic phase transition
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U2 - 10.1016/j.ssi.2020.115291
DO - 10.1016/j.ssi.2020.115291
M3 - Article
AN - SCOPUS:85083873058
VL - 349
JO - Solid State Ionics
JF - Solid State Ionics
SN - 0167-2738
M1 - 115291
ER -