Phase diagram, crystal growth and characterization of Mn-substituted ZnGeAs2 system

Abstract In order to obtain newer materials with better performance of diluted magnetic semiconductors (DMS), we have constructed the phase diagrams of Mn-substituted ZnGeAs 2 systems, using the differential thermal analysis and powder X-ray diffraction. Based on these phase diagrams, which show how to obtain Mn-substituted solid solutions, bulk crystals were grown by the horizontal gradient freezing method. The Mn compositional region in these solid solutions may be narrow below about 5%. The optical band gaps of Mn-substituted solid solutions are larger than that of non-doped ZnGeAs 2 , indicating that Mn atoms are substituted in cation-sites.