Temperature dependence of the dynamics of ultrafine particles in a polymeric network
Simple model systems with pronounced dynamical features will help to get a deeper insight into the complicated dynamics of large molecular networks. We investigated the bounded diffusion of ultrafine Fe(OH)3 particles (∼30 Å in diameter) in the three-dimensional network of the cation exchanger Dowex 50 W which was solvated with a water solution of sucrose (60 wt%). Mössbauer spectra were recorded in the temperature range from 80 K to 305 K. At temperatures above 250 K broad diffusional lines of different widths appear in the spectrum proving the bounded nature of the diffusion. The line widths strongly increase with temperature to values of several hundred mm/s. Around 300 K a large portion of the area escapes even from the largest window of observation used in our experiments (±550 mm/s).
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- R.L. Mössbauer, Hyp. Int. 33 (1987) 199–222.Google Scholar
- K.V. Shaitan and A.B. Rubin, Biofizika 25 (1980) 790–802.Google Scholar
- A.M. Afanasev and V.E. Sedov, Phys. Stat. Sol. (B) 131 (1985) 299–308.Google Scholar
- A.M. Afanasev, L.V. Bashkeev, A.S. Plachinda, V.E. Sedov and V.I. Khromov, Sov. Chem. Phys., to be published.Google Scholar
- F. Parak, M. Fischer and G.U. Nienhaus (1989), J. Mol. Liquids, in press.Google Scholar