The Avrami–Johnson–Mehl model and irradiation induced phase changes in silicon

✍ Scribed by G. Carter

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 130 KB
• Volume: 53
• Category: Article
• ISSN: 0042-207X
• DOI: 10.1016/s0042-207x(98)00346-7

✦ Synopsis

It is shown that the Avrami-Johnson-Mehl (AJM) model of phase transformations (P.G. Shewmon, Transformations in Metals, McGraw-Hill,New York,1969) requires modification to include the finite volume transformed in a nucleation event and that this can change, subtly, the kinetics of transformation. It is then demonstrated that AJM approaches cannot satisfactorily explain experimental measurements of ion irradiation induced amorphisation processes in Si and a model, based upon the thermal and radiation induced annealing of the instantaneous amorphous fraction is developed. Although more complex the results are shown to compare qualitatively with the limited experimental data available on ion flux density and temperature dependencies of amorphisation rates and to correctly predict trends. Irradiation induced crystallisation is amenable to a modified AJM approach but inclusion of a time varying finite amorphised volume is necessary.