Pressure‐induced phase transitions and polytypic structures in III‐Nitrides

In this work, we have calculated ab initio the equation of state for the rocksalt, zincblende, wurtzite, 4H and 6H hexagonal modifications of GaN and InN, as well as both the wurtzite-to-rocksalt and zincblende-to-rocksalt phase transitions in these materials. Based on our results, the former phase transition is irreversible, and the zincblende structures is not obtained by applying pressure. Instead, polytypic structures, similar to those observed in SiC, can be obtained. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)