Accession Number : AD0787667

Title :   Anomalous Diffusion in Non-Metals (Origin and Effects of Internal Electric Fields),

Corporate Author : UTAH UNIV SALT LAKE CITY DEPT OF PHYSICS

Personal Author(s) : DeFord,J. W. ; Johnson,O. W.

Report Date : 1974

Pagination or Media Count : 37

Abstract : When electrically active impurities or defects diffuse in a material with a band gap > 10 kT, the changing concentration of these ions may result in internal electric fields which will significantly alter the diffusion process, and result in gross misinterpretation of diffusion experiments. Equations are derived which describe the diffusion of interstitial impurities in such a system, and which take proper account of compensating immobile impurities. A technique for numerical solution of these equations is described and the results of calculations for the case of H(+) in TiO2 are presented. These calculations predict a large enhancement of the overall diffusion rate and a very distinctive concentration profile. Experimental results for the H(+)-TiO2 system are presented, which agree quantitatively with calculations. (Modified author abstract)

Descriptors :   *Diffusion, *Titanium oxides, *Hydrogen, Electric fields, Band theory of solids, Impurities, Diffusion theory, Ions

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE