First-principles study of the Pd–Si system and Pd(0 0 1)/SiC(0 0 1) hetero-structure

Abstract

First-principles molecular dynamics simulations of the Pd(001)/3C–SiC(001) nano-layered structure were carried out at different temperatures ranging from 300 to 2100K. Various PdSi (Pnma, Fm3¯m, P6¯m2, Pm3¯m), Pd2Si (P6¯2m, P63/mmc, P3¯m1, P3¯1m) and Pd3Si (Pnma, P6322, Pm3¯m, I4/mmm) structures under pressure were studied to identify the structure of the Pd/Si and Pd/C interfaces in the Pd/SiC systems at high temperatures. It was found that a large atomic mixing at the Pd/Si interface occurred at 1500–1800K, whereas the Pd/C interface remained sharp even at the highest temperature of 2100K. At the Pd/C interface, voids and a graphite-like clustering were detected. Palladium and silicon atoms interact at the Pd/Si interface to mostly form C22-Pd2Si and D011-Pd3Si fragments, in agreement with experiment.