Magnetic, kinetic, and optical properties of new high‐pressure phases in the system Cr–GaSb: Ab initio density functional theory study

The structural, transport, magnetic, and optical properties of high‐pressure‐synthesized metastable compounds CrGaSb and CrGa 2 Sb 2 are calculated from first principles. In addition to theoretical results, new X‐ray structural measurements of CrGa 2 Sb 2 up to 9 GPa are reported. Both high‐pressure phases CrGaSb and CrGa 2 Sb 2 are found to be at the edge between metal and semiconductor, which implies that the standard density functional theory predictions may be misleading. To clarify the situation, a study is conducted whether the results depend significantly on the approximation used for the exchange–correlation potential. A possible effect of slight nonstoichiometry found in the CrGa 2 Sb 2 samples is also investigated. The calculation results agree with most available experimental data and are internally consistent, which provides the assurance that, as a whole, they give a reliable picture of electronic properties in CrGaSb and CrGa 2 Sb 2 . © 2012 Wiley Periodicals, Inc.