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

Highlights: • A large atomic mixing at the Pd/Si interface occurs at 1500–1800 K. • The Pd/C interface remains sharp even at the highest temperature of 2100 K. • At the Pd/C interface, voids and a graphite-like clustering are detected. • At the Pd/Si interface C22-Pd₂Si and D0₁₁-Pd₃Si fragments form, in agreement with experiment. - Abstract: First-principles molecular dynamics simulations of the Pd(0 0 1)/3C–SiC(0 0 1) nano-layered structure were carried out at different temperatures ranging from 300 to 2100 K. 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 1500–1800 K, whereas the Pd/C interface remained sharp even at the highest temperature of 2100 K. 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