Accession Number : AD0686661

Title :   DISLOCATION PIPE DIFFUSION IN SILVER SINGLE CRYSTALS,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON D C

Personal Author(s) : Vardiman,R. G. ; Achter,M. R.

Report Date : 25 MAR 1969

Pagination or Media Count : 14

Abstract : A chemical sectioning technique was developed for the measurement of self diffusion in silver at low temperatures. (Silver was chosen because of its well-established high-temperature behavior, and because of the availability of the long-lived isotope Ag(110)). Layers of 100A or less are removed by an iodine reaction, and diffusion coefficients D as low as 2 x 10 to the minus 17th power sq cm/sec have been measured. A large enhancement over extrapolated high-temperature values, which has been observed below T sub m/2, is attributed to dislocation short circuiting. Determination of the pipe diffusion coefficient at the lowest measured temperature, where Harrison's type C kinetics are expected to apply, yields good agreement with the pipe diffusion coefficients D sub p calculated from published data obtained by another technique. (Author)

Descriptors :   (*DISLOCATIONS, DIFFUSION), (*SILVER, TRANSPORT PROPERTIES), SINGLE CRYSTALS, TRACER STUDIES

Subject Categories : Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE