Reconstruction and thermal stability of the cubic SiC(001) surfaces

The (001) surfaces of cubic SiC were investigated with ab initio molecular dynamics simulations. We show that C-terminated surfaces can have different c(2 x 2) and p(2 x 1) reconstructions, depending on preparation conditions and thermal treatment, and we suggest experimental probes to identify the various reconstructed geometries. Furthermore, we show that Si-terminated surfaces exhibit a weak c(2 x 1) reconstruction at T = 0, whereas above room temperature they oscillate between a dimer row and an ideal geometry below 500 K, and sample several patterns including a c(4 x 2) above 500 K.