Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
AMORPHOUS POLYMORPHISM IN ICE INVESTIGATED BY INELASTIC NEUTRON-SCATTERING
Autore:
SCHOBER H; KOZA M; TOLLE A; FUJARA F; ANGELL CA; BOHMER R;
Indirizzi:
INST MAX VON LAUE PAUL LANGEVIN,BP 156X F-38042 GRENOBLE FRANCE UNIV DORTMUND,FACHBEREICH PHYS D-44221 DORTMUND GERMANY ARIZONA STATE UNIV,DEPT CHEM TEMPE AZ 85287 UNIVERSITAT MAINZ,INST PHYS CHEM D-55099 MAINZ GERMANY
Titolo Testata:
Physica. B, Condensed matter
, volume: 241, anno: 1997,
pagine: 897 - 902
SICI:
0921-4526(1997)241:<897:APIIIB>2.0.ZU;2-E
Fonte:
ISI
Lingua:
ENG
Soggetto:
GLASS-TRANSITION; HEAT-CAPACITY; X-RAY; WATER; BEHAVIOR; IH;
Keywords:
AMORPHOUS ICE; ICE; POLYMORPHISM;
Tipo documento:
Article
Natura:
Periodico
Citazioni:
19
Recensione:
Indirizzi per estratti:
Citazione:
H. Schober et al., "AMORPHOUS POLYMORPHISM IN ICE INVESTIGATED BY INELASTIC NEUTRON-SCATTERING", Physica. B, Condensed matter, 241, 1997, pp. 897-902

Abstract

High-density I-hda and low-density I-lda amorphous ice phases have been investigated by inelastic neutron scattering (INS) with emphasis onthe energy window from 0.5 to 20 meV. At variance with earlier measurements the spectra in the I-hda phase show a simple omega(2) behaviourin the acoustic region and the temperature dependence is found to be harmonic. I-hda converts with a strongly temperature-dependent rate towards I-lda ice. We have investigated in detail the time evolution of both the static and dynamic response functions at several temperatures. Elastic small-angle signals indicate the presence of strong heterogeneities at the early stages of the conversion process. At least two different time scales are present in the transition. The structural changes are reflected in the frequency distribution. The first peak in thephonon density-of-states softens appreciably when going from I-hda toI-lda. In the acoustic region there is evidence that I-lda is softer than both I-hda and crystalline cubic ice I-c. No signs of a fast ps process related to melting can be detected in the dynamics. (C) 1998 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 07/07/20 alle ore 22:19:08