PROCESSUS DE TRANSPORT DANS LES OXYDESCATION SELF DIFFUSION IN RUTILEReport as inadecuate




PROCESSUS DE TRANSPORT DANS LES OXYDESCATION SELF DIFFUSION IN RUTILE - Download this document for free, or read online. Document in PDF available to download.



Abstract : Diffusion in rutile TiO2 is characterized by extreme anisotropy with very large diffusion rates along the c-direction in the body-centered tetragonal structure for interstitial elements such as lithium and boron. In marked contrast, substitutional elements appear to diffuse in the a- and c-directions at similar rates. We have examined cation self diffusion in TiO2 both theoretically and experimentally and find that the relative diffusion coefficients in the two directions can be used along with their partial correlation functions to identify the jumps taking place in the bct cation sublattice. We considered three types of possible jumps : a-direction, c-direction, and along the body diagonal. The information obtained shows that the diagonal jump cannot be unique for this system but must be accompaied by a significant fraction of c-direction jumps. Concepts developed in this research may be extended to other anisotropic systems to assist in identification of jump mechanisms for the atomic transport processes.





Author: T. Lundy W. Coghlan

Source: https://hal.archives-ouvertes.fr/



DOWNLOAD PDF




Related documents