Molecular dynamics simulation of thermodynamic properties of YAG

In this paper we study the thermodynamic properties of Y_3Al_5O_12 (YAG) by using molecular dynamic method combined with two- and three-body potentials. The dependences of melting process, elastic constant and diffusion coefficient on temperature of crystal YAG are simulated and compared with the experimental results. Our results show that anion O has the biggest self-diffusivity and cation Y has the smallest self-diffusivity in a crystal YAG. The calculated diffusion activation energies of ions O, Al and Y are 282.55, 439.46, 469.71kJ/mol, respectively. Comparing with experimental creep activation energy of YAG confirms that cation Y can restrict the diffusional creep rate of crystal YAG.