A comparative study between MEAM and Tersoff potentials on the characteristics of melting and solidification of carborundum

Abstract

Molecular dynamic simulations of bulk melting, surface melting and crystal growth of SiC are carried out. The atomic interactions in SiC are calculated by MEAM and Tersoff potentials separately. The results show that the bulk melting of SiC with MEAM potential exhibits its relations to temperature similar to that with Tersoff potential, while can be indicated by the mean atomic energy, Lindemann index and structure order parameter. The difference between them is the bulk melt point: MEAM is 4250 K, while Tersoff is 4750 K. At the same superheat degree, the velocities of surface melting of SiC separately, with MEAM and Tersoff potentials are in substantial agreement. But at the same absolute temperature, the surface melting of SiC with MEAM potential is faster than that which the Tersoff potential, which is due to the difference in thermodynamic melting point. The Measured value of the thermodynamic melting point of MEAM is 3338 K compared with 3430 K of Tersoff. On the crystal growth side, the crystal growth velocity of SiC with MEAM potential is related to the undercooling. The fastest velocity corresponds to the undercooling of 400 K. However, the crystal of SiC with Tersoff potential cannot grow in the undercooling of 0 K1000 K. Overall, the MEAM potential is better than Tersoff potential in the sense of describing the melting and solidification of carborundum.