A two-dimensional model of a nano-sized amorphous layer embedded in a perfect crystal has been developed, and the amorphous-to-crystalline (a-c) transition in 3C-SiC at 2000 K has been studied using molecular dynamics methods, with simulation times of up to 88 ns. Analysis of the a-c interfaces reveals that the recovery of the bond defects existing at the a-c interfaces plays an important role in recrystallization. During the recrystallization process, a second ordered phase, crystalline 2H-SiC, can be nucleated and grow, and is stable for long simulation times. The crystallization mechanism is a two-step process that is separated by a longer period of second-phase stability. The kink sites formed at the interfaces between 2H- and 3C-SiC provide a low energy path for 2H-SiC atoms to transfer to 3C-SiC atoms, which can be defined as a solid-phase epitaxial transformation (SPET). It is observed that the nano-sized amorphous structure can be fully recrystallized at 2000 K in SiC, which is in agreement with experimental observations.
Revised: March 8, 2005 |
Published: January 1, 2005
Citation
Gao F., R. Devanathan, Y. Zhang, and W.J. Weber. 2005.Annealing Simulations of Nano-Sized Amorphous Structures in SiC.Nuclear Instruments and Methods in Physics Research. Section B, Beam Interactions with Materials and Atoms 228, no. 1-4:282-287.PNNL-SA-42095.