New Microscopic Mechanism for Secondary Relaxation in Glasses

Journal Article · Fri Aug 14 00:00:00 EDT 2009 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.103.075701· OSTI ID:21370667

Zuriaga, M ^[1]; Pardo, L C; Tamarit, J Ll; Veglio, N; Barrio, M ^[2]; Lunkenheimer, P; Loidl, A ^[3]; Bermejo, F J ^[4]

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1. IFFAMAF, Facultad de Matematica, Astronomia y Fisica, Universidad Nacional de Cordoba, Ciudad Universitaria, 5000 Cordoba (Argentina)
2. Grup de Caracteritzacio de Materials, Departament de Fisica i Enginyeria Nuclear, ETSEIB, Universitat Politecnica de Catalunya, Diagonal 647, 08028 Barcelona, Catalonia (Spain)
3. Experimental Physics V, Center for Electronic Correlations and Magnetism, University of Augsburg, 86135 Augsburg (Germany)
4. CSIC-Department of Electricity and Electronics, University of the Basque Country, P.O. Box 664, 48080 Bilbao (Spain)

The dynamics of simple molecular systems showing glassy properties has been explored by dielectric spectroscopy and nuclear quadrupole resonance (NQR) on the halogenomethanes CBr{sub 2}Cl{sub 2} and CBrCl{sub 3} in their low-temperature monoclinic phases. The dielectric spectra display features which correspond to alpha- and beta-relaxation processes, commonly observed in canonical glass formers. NQR experiments, also performed in the ergodic monoclinic phase of CCl{sub 4}, enable the determination of the microscopic mechanism underlying the beta dynamics in these simple model glasses: Molecules that are nonequivalent with respect to their molecular environment perform reorientational jumps at different time scales. Thus our findings reveal another mechanism that can give rise to typical beta-relaxation behavior, raising some doubt about the existence of a universal explanation of this phenomenon.

• OSTI ID: 21370667
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 7 Vol. 103; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BROMIDES
BROMINE COMPOUNDS
CARBON TETRACHLORIDE
CHLORINATED ALIPHATIC HYDROCARBONS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DIELECTRIC MATERIALS
GLASS
HALIDES
HALOGEN COMPOUNDS
HALOGENATED ALIPHATIC HYDROCARBONS
MATERIALS
MONOCLINIC LATTICES
NUCLEAR QUADRUPOLE RESONANCE
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
RESONANCE
SPECTROSCOPY