Study on the Phase Transition ofK₃D_xH_1-x(SO₄)₂by the Raman Scattering of the Internalν₂Mode

The origin of disorder in CH 3 HgX (X = Cl, Br and I) crystals investigated by temperature dependent Raman spectroscopy

“…4) support the hypothesis of a new phase transition in CH 3 HgBr below T d . Such temperature behaviour of a band attributed to the internal mode was reported for ND 4 TeBr 6 [44] and K 3 D x H 1−x (SO 4 ) 2 [45]. In both cases a phase transition was simultaneously taking place.…”

Proton spin-lattice relaxation and local symmetry of the H bond inRb3H(SO4Mikac1, Zalar2, Dolinšek3 et al. 2000Phys. Rev. B12170View full textAdd to dashboardCite

“…The above hypothesis of a transition from a double to a symmetric single minimum type H-bond potential on cooling does not seem to be supported by Raman-scattering data in K 3 D 1Ϫx H x ͑SO 4 ͒ 2 type crystals. 13 The data were rather interpreted as pointing to the existence of a double-minimum H-bond potential in the protonated compound even at 20 K. A deuteron spin-lattice relaxation time anomaly recently observed at T c in Rb 3 D͑SO 4 ͒ 2 was similarly interpreted as being incompatible with the existence of a center of symmetry in the middle of the O-D¯O bond. 3 Infrared measurements as well have not shown the expected change in the OH stretching band on going from an asymmetric to a symmetric H-bond potential with decreasing temperature.…”

The Phase Transition of (ND 4 ) 3 D(SO 4 ) 2 Studied with Raman Scattering

“…It was shown [7] that Raman scattering study of sulfate ions is useful to obtain the characteristic time of flip-flop motions of hydrogens in hydrogen bonds and to see whether hydrogen is located at the off-center position or at 132 M. KASAHARA and T. YAGI the center position in the ordered phase. Hence, in order to make the relation between hydrogens and the phase transition clear, Raman scattering study was carried out and is reported in this paper.…”