TY - JOUR
T1 - Crystal structure of the "intermediate" phase of the protonic conductor Rb3H(SeO4)2
AU - Merinov, B. V.
AU - Haile, S. M.
AU - Bismayer, U.
N1 - Funding Information:
The authors thank Dr. Tregubchenko for providing crystals and Dr. Morgenroth for aid with the X-ray experiment. Dane Boysen kindly assisted with the optical microscopy. Financial support from the Alexander von Humboldt Foundation and the National Science Foundation is gratefully acknowledged.
PY - 2002/2/2
Y1 - 2002/2/2
N2 - The crystal structure of Rb3H(SeO4)2 in its "intermediate" phase has been determined at T = 449K using synchrotron radiation (λ = 1.00798 Å). The phase is monoclinic, space group C2/m, with a = 10.691(3) Å, b = 6.167(2) Å, c = 8.429(4) Å, β = 115.00(1) V = 503.6(4) Å3, Mr = 543.32, Dx = 3.58g cm-3, μ = 81.3 cm-1, and Z = 2. Refinement was carried out to a residual Rw = 0.049 for 1002 unique reflections with I>3σ(I). Optical studies revealed the formation of a complex domain structure within this phase, and refinements were thus carried out assuming a twinned crystal model. Hydrogen bonds are arranged in a one-dimensional chain extending along b. Such a network is intermediate between that found in Rb3H(SeO4)2 at room temperature, in which selenate groups are linked into well-defined dimers (zero-dimensional), and that found in Rb3H(SeO4)2 at high temperature, in which the network is two-dimensional. The highly twinned structure suggests that macroscopic crystals will exhibit isotropic conductivity within the ab plane (similar to the high-temperature, trigonal phase) despite the anisotropic hydrogen bond arrangement within individual domains.
AB - The crystal structure of Rb3H(SeO4)2 in its "intermediate" phase has been determined at T = 449K using synchrotron radiation (λ = 1.00798 Å). The phase is monoclinic, space group C2/m, with a = 10.691(3) Å, b = 6.167(2) Å, c = 8.429(4) Å, β = 115.00(1) V = 503.6(4) Å3, Mr = 543.32, Dx = 3.58g cm-3, μ = 81.3 cm-1, and Z = 2. Refinement was carried out to a residual Rw = 0.049 for 1002 unique reflections with I>3σ(I). Optical studies revealed the formation of a complex domain structure within this phase, and refinements were thus carried out assuming a twinned crystal model. Hydrogen bonds are arranged in a one-dimensional chain extending along b. Such a network is intermediate between that found in Rb3H(SeO4)2 at room temperature, in which selenate groups are linked into well-defined dimers (zero-dimensional), and that found in Rb3H(SeO4)2 at high temperature, in which the network is two-dimensional. The highly twinned structure suggests that macroscopic crystals will exhibit isotropic conductivity within the ab plane (similar to the high-temperature, trigonal phase) despite the anisotropic hydrogen bond arrangement within individual domains.
KW - Crystal structure
KW - Protonic conductor
KW - Single crystal
KW - Synchrotron radiation
KW - Trirubidium hydrogen biselenate
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U2 - 10.1016/S0167-2738(01)01033-5
DO - 10.1016/S0167-2738(01)01033-5
M3 - Article
AN - SCOPUS:0037006222
SN - 0167-2738
VL - 146
SP - 355
EP - 365
JO - Solid State Ionics
JF - Solid State Ionics
IS - 3-4
ER -