Pretransitional dynamics of the structural phase transition in anthracene-TCNB: A comparison of Raman-scattering and inelastic-neutron-scattering experiments

Abstract DSC measurements performed at 95 -290 K have shown that [Mn(H 2 O) 6 ](CIO 4) 2 possesses, besides a high-temperature phase, existing above 323 K, four low-temperature solid phases. The inelastic incoherent neutron scattering (IINS) spectra and neutron powder diffraction (NPD) pat-terns registered at 20 -290 K have supported the DSC results and provided evidence that the investigated substance possesses even more than five solid phases. The IINS spectra have shown that in the room-temperature phase, water molecules perform fast stochastic reorientation at the picosecond scale. The orientational disorder characteristic for the room-temperature phase can be easily overcooled and frozen. Even by relatively slow cooling at ca. 40 K/hour a metastable, orientational (protonic) glass phase is formed below ca. 160 K. Below ca. 100 K, a structural phase transition was observed by the NPD, however the IINS spectra indicate existence of the pure ordered low-temperature phase only after annealing the sample for a few hours at 100 K. On heating, a structural phase transition takes place at ca. 120 K, and at ca. 225 K water molecules begin fast reorientation.

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Pressure-induced structural phase transition of CdS microcrystals studied by raman scattering

Journal of Physics and Chemistry of Solids ◽

10.1016/0022-3697(94)00227-4 ◽

1995 ◽

Vol 56 (3-4) ◽

pp. 491-494 ◽

Cited By ~ 8

Author(s):

Toshihiro Arai ◽

Toshiharu Makino ◽

Masaaki Arai ◽

Kiyoto Matsuishi ◽

Seinosuke Onari

Keyword(s):

Phase Transition ◽

Raman Scattering ◽

Structural Phase Transition ◽

Structural Phase

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Pressure-induced structural phase transition in Na0.5Bi4.5Ti4O15 by Raman scattering

Physics Letters A ◽

10.1016/0375-9601(96)00352-0 ◽

1996 ◽

Vol 218 (1-2) ◽

pp. 94-98 ◽

Cited By ~ 9

Author(s):

Jianjun Liu ◽

Chunxiao Gao ◽

Guangtian Zou ◽

Yanrong Jin

Keyword(s):

Phase Transition ◽

Raman Scattering ◽

Structural Phase Transition ◽

Structural Phase

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High-pressure Raman scattering and inelastic neutron scattering studies of triaminotrinitrobenzene

The Journal of Physical Chemistry ◽

10.1021/j100177a088 ◽

1991 ◽

Vol 95 (24) ◽

pp. 10103-10109 ◽

Cited By ~ 25

Author(s):

Sushil K. Satija ◽

Basil Swanson ◽

Juergen Eckert ◽

J. A. Goldstone

Keyword(s):

High Pressure ◽

Raman Scattering ◽

Neutron Scattering ◽

Inelastic Neutron Scattering ◽

Inelastic Neutron

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NH3 reorientation in phases I, II, and III of Ni(NH3)6(NO3)2

Canadian Journal of Chemistry ◽

10.1139/v88-120 ◽

1988 ◽

Vol 66 (4) ◽

pp. 692-697 ◽

Cited By ~ 11

Author(s):

Gordon J. Kearley ◽

Herma Blank

Keyword(s):

Phase Transition ◽

Neutron Scattering ◽

Strong Interaction ◽

Rotational Motion ◽

Inelastic Neutron Scattering ◽

Inelastic Neutron ◽

Phase Iii ◽

Single Type ◽

Quasielastic Neutron ◽

Quasielastic Neutron Scattering

The inelastic neutron scattering (INS) spectra of rotational tunnelling and librations of NH3 ligands in phase III of Ni(NH3)6(NO3)2 are not consistent with a rotational hindrance potential containing only cos [Formula: see text] terms owing to strong interaction between neighboring cations. This type of interaction, and motion of the whole cation, also influences the classical reorientational motions involving displacement of the H atoms, where the overall radius of rotation is consistently greater than the 0.9 Å expected for isolated NH3 rotors. Quasielastic neutron scattering (QNS) suggests that in phase III there are two sublattices of cations, one of which becomes completely disordered (with respect to the NH3 rotors) at the III–II phase transition. Disorder of the second sublattice marks the II–I transformation where only a single type of rotational motion is found.

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