Lim AR. (1)H and (87)Rb nuclear magnetic resonance study of the order-disorder phase transition of RbHSeO(4) single crystals.
SOLID STATE NUCLEAR MAGNETIC RESONANCE 2008;
34:162-166. [PMID:
18693088 DOI:
10.1016/j.ssnmr.2008.06.002]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2008] [Revised: 06/18/2008] [Accepted: 06/22/2008] [Indexed: 05/26/2023]
Abstract
The ferroelectric phase transition at T(C2) (=370K) in RbHSeO(4) has been studied by (1)H and (87)Rb solid-state NMR. Although not large, the spin-lattice relaxation time, T(1), and the spin-spin relaxation time, T(2), of rubidium and of the alpha- and beta-type protons show distinct change near the phase transition. The intensity of the signal due to the alpha-type protons decreases with increasing temperature, and the intensity of alpha-type protons is quite weak above 330K: at a temperature which is about 40K lower than the phase transition temperature, the ordering of the alpha-type protons occurs. The alpha-type protons in the ferroelectric phase lead to a noticeable change in the proton magnetic resonance spectra. Our study of the (1)H spectra shows that the ferroelectric phase transition in RbHSeO(4) is of order-disorder type and is due to the ordering of protons in hydrogen bonds.
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