Role of nonequilibrium vacancies at interdiffusion in a crystal without sinks

Main Article Content

О. М. Rymar
А. М. Gusak

Abstract

For the first time the results of interdiffusion n simulation in fcc structure between pure components A and B by the kinetic mean-field method are presented. Nonequilibrium vacancies redistribution is taken into account in the system. Initial distribution of the components with average concentration 0.5 is chosen to be sinusoidal. Initial vacancy concentration is chosen to be constant. From the beginning, we have a concentration gradient of A and B. Concentration profiles evolution at various combinations of pair interaction energies is studied. In case of equal frequency factors of the components , the vacancy concentration remains constant everywhere. If frequency factors are not the same, the distribution of vacancies becomes sinusoidal. At the same time, vacancies start to accumulate on the side of material with lower melting point. In the symmetric case ( the same energy values of pairwise interactions A-A and B-B ) there occurs the formation of an ordered phase AB. The formation of an ordered phase AB also has been observed after introduction of asymmetry to the system but with asymmetric nature of the redistribution of vacancies.

Article Details

Section
Mathematical and Calculation Physics

References

1. Martin G. (1990). Atomic mobility in Cahn’s diffusion model. Physical Review B, 41(4), 2279-2283.
2. Beke D. L., Erdélyi Z. Erdélyi, Szabó I.A. Szabó, Cserháti C. (2004). Nanoscale Effects in Diffusion. Journal of Metastable and Nanocrystalline Materials, 19, 107-128.
3. Beke D. L., Erdélyi Z. (2006). Diffusion under large driving forces. Defect and Diffusion Forum, 249, 119-126.
4. Beke D. L., Erdélyi Z. (2007). Growth Kinetics on Nanoscale: Finite Diffusion Permeability of Interfaces. Defect and Diffusion Forum, 266, 1-12.
5. Storozhuk N.V., Sopiga K.V. and Gusak A.M. (2012). Mean-field and quasi-phasefield models of nucleation and phase competition in reactive diffusion. Philosophical Magazine, 93 (16), 1999-2012.
6. Sopiha K.V. (2014). Mean field diffusion models and ordering in alloys. (Master thesis, Cherkasy national university named after B. Chmelnytsky, Cherkasy, Ukraine).
7. Gusak A. M., Zaporozhets T. V., Lyashenko Yu. O., Kornienko S.V., Pasichnyy M. O., Shirinyan A. S. (2010). Diffusion-controlled Solid State Reactions: In Alloys, Thin Films and Nanosystems. WILEY-VCH.
8. Gurov K. P. Gusak A. M. (1985). Physics of Metals and Metallography, 59, 1062.
9. Nazarov A.V. and Gurov K. P. (1974). Physics of Metals and Metallography, 37, 496.
10. Klimontovich Yu. L. (1982). Statistical physics. MoscowNauka. (in Rus.)