Growth of bulk Ga1-xMnxN single crystals

Mixtures of powders of gallium nitride and manganese were annealed in a str eam of ammonia at temperatures from the range of 1200-1250 degreesC. The pr ocedure resulted in preparation of bulk single crystals of gallium nitride of dimensions up to 2.7 x 1.5 x 0.5 mm and containing up to 2% of Mn by wei ght. The influence of temperature, ammonia flow rate and manganese concentr ation in the substrate material on the doping level of the obtained bulk cr ystals was studied. The concentration of manganese was determined by means of an electron microprobe method. Raman investigations supported the conclu sion on the well ordered structure of the prepared crystals. The measuremen ts done by a superconducting quantum interferometer showed that the crystal s doped with manganese ions manifested paramagnetic properties. (C) 2001 Pu blished by Elsevier Science B.V.