Landolt-Börnstein - Group III Condensed Matter

8 Diffusion in molecular solids

Abstract

This chapter focuses on the diffusion in molecular solids, excluding the work on macromolecules and polymers. Molecular solids are usually classified into three types; the rare gas solids, plastic and non-plastic solids. The reliability of the data that are listed are strongly dependent on the method of measurement and some brief comments on methods employed for molecular solids are necessary. Although the prime aim of this chapter is to present the experimental data some comments on the theory of diffusion in molecular solids will assist the reader. Thermodynamic properties are used in gaining an understanding of the diffusion in molecular crystals and the first set of tables records the key parameters. These parameters are generally recorded in the following order: compound name, alternative names, transition temperature to plastic phase, triple point temperature, melting temperature, latent heat of sublimation, entropy of fusion and crystal structure. Diffusion data are grouped into four general classes: self-diffusion, impurity diffusion, pressure effect on diffusion and isotope mass effect diffusion. The figures presented in the chapter are not intended to be comprehensive representations of all the data presented in the tables. The aim is to illustrate the type of data that is available for molecular crystals. Hence the figures include typical raw data plots from the various techniques used for these materials, e.g. NMR, creep and the various radiotracer experiments. Some radiotracer penetration profiles have been included to present a picture of the quality of raw data that can be obtained.

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Title
8 Diffusion in molecular solids
Book Title
Diffusion in Non-Metallic Solids (Part 1)
Book DOI
10.1007/b59654
Chapter DOI
10.1007/10542761_15
Part of
Landolt-Börnstein - Group III Condensed Matter
Volume
33B1
Editors
  • D. L. Beke
  • Authors
  • A. V. Chadwick
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