GaN needles and platelets were grown at atmospheric pressure using NH_3 in H_2. The growth, with an NH_3 to H_2 partial pressure ratio of about 1:1000, was maintained for 10 days at a temperature of 930 degree C. The NH_3 partial pressure was controlled by a novel continuous titration apparatus. The GaN needles preferentially formed on the walls of the quartz boat, while the platelets were formed at the location formerly occupied by the Ga source material and were surrounded by amorphous GaN deposits. The maximum dimensions of the needles obtained were 3 mm by 50 microns, while the largest platelets were 1 by 1 mm. Both needles and platelets were conducting. Scanning Electron Microscopy, Atomic Force Microscopy, Scanning Tunneling Microscopy, and Reflection High Energy Electron Diffraction was performed on those crystals and the results compared to MBE grown GaN using NH_3. Needles grow preferentially along the c-axis by propagation of the terraces. AFM images showed terraces with mean lengths of 5 um near the top of the needles and approximately 50 um near the base of the needles. These terraces were nearly atomically smooth.

* Partially supported by AFOSR Grant F49620-95-1-0431