Pressure-induced phase transformation of 4H-SiC: An ab initio constant-pressure study

The stability of 4H-SiC at high pressure is studied using a constant-pressure ab initio technique. For the first time, a first-order phase transformation into a rocksalt structure is observed in this material. The 4H-to-RS phase transformation is associated with the shear deformation and its transformation mechanism is different from that of the 2H-to-rocksalt and 6H-to-rocksalt phase transformations. The 4H-to-rocksalt phase change is also studied by total-energy calculations. Copyright (C) EPLA, 2009