6533b85dfe1ef96bd12bf288
RESEARCH PRODUCT
Structural fluctuations in glass-forming liquids: Mössbauer spectroscopy on iron in glycerol.
G. U. NienhausHans FrauenfelderFritz G. Paraksubject
Materials scienceNuclear magnetic resonanceAbsorption spectroscopyMössbauer effectImpurityRelaxation (NMR)Analytical chemistryActivation energyAtmospheric temperature rangeSupercoolingSpectral linedescription
M\"ossbauer absorption spectra of $^{57}\mathrm{Fe}^{2+}$ dissolved in a glycerol-water mixture have been measured over a wide temperature range (80--275 K). In the supercooled liquid state the shapes of the spectra depend strongly on temperature. The M\"ossbauer spectra can be fit with jump diffusion with a Cole-Davidson distribution of fluctuation times. The results are in agreement with those obtained from dielectric and ultrasonic volume relaxations, proving that the \ensuremath{\alpha} relaxation of viscous liquids is responsible for the line broadening of the spectra. From the temperature dependence of the integrated area of the M\"ossbauer spectrum a second dynamic process is inferred. Its activation energy of 31.4 kJ/mol is typical for the \ensuremath{\beta} relaxation.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1991-02-01 | Physical review. B, Condensed matter |