Abstract Radiotracer, serial sectioning studies of self-diffusion have been made in ultra-pure single crystals of the triclinic phase of n-eicosane (C20H42) in the temperature range 295-309 K. The crystals of this solid readily undergo plastic deformation. Consequently, crystals grown from the melt (Bridgman Technique) contain a high concentration of dislocations, slip bands and polygonized boundaries. Diffusion along these defects (pipe-diffusion) contributes significantly to the total penetration of radioactivity and hence decreases the precision with which lattice self-diffusion coefficients can be evaluated. An attempt is made to assess this interference and to correct data. As might be expected in such anisotropic materials, there is a significant difference in self-diffusion parallel (D‖) and perpendicular (D‖) to the basal (001) planes. The latter can be shown with reasonable precision to follow a temperature dependence. D┴ = 9 × 1044 exp(−341 + 18 kJ mol−1/RT). The former cannot be denned due to t...
[1]
A. Damask,et al.
The growth and perfection of phenanthrene single crystals. 1. Purification and single crystal growth
,
1974
.
[2]
J. Sherwood,et al.
Self-diffusion in a-sulphur crystals
,
1974
.
[3]
L. Slifkin,et al.
Point Defects in Solids
,
1972
.
[4]
E. Passaglia,et al.
Internal‐Friction Study of High‐Purity Single Crystals of n Eicosane (C20H42)
,
1971
.
[5]
E. Passaglia,et al.
Crystal data on n‐eicosane (C20H42)
,
1970
.
[6]
A. Claire.
The analysis of grain boundary diffusion measurements
,
1963
.
[7]
Toshiro Suzuoka,et al.
Lattice and Grain Boundary Diffusion in Polycrystals
,
1961
.
[8]
E. W. Hart.
On the role of dislocations in bulk diffusion
,
1957
.
[9]
R. Whipple.
CXXXVIII. Concentration contours in grain boundary diffusion
,
1954
.