Ammonothermal Conversion of Cyclotrigallazane to GaN:  Synthesis of Nanocrystalline and Cubic GaN from [H2GaNH2]3

• Published in: Chemistry of materials Vol. 12; no. 4; pp. 1003 - 1010
• Main Authors: Jegier, Jolin A, McKernan, Stuart, Purdy, Andrew P, Gladfelter, Wayne L
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 17.04.2000
• Subjects: Chemistry; Colloidal state and disperse state; Cross-disciplinary physics: materials science; rheology; Disperse systems; Elements and non-metal compounds (oxides, hydroxides, hydrides, sulfides, carbides, ...); Exact sciences and technology; General and physical chemistry; Growth from solutions; Inorganic chemistry and origins of life; Materials science; Methods of crystal growth; physics of crystal growth; Nanoscale materials and structures: fabrication and characterization; Physics; Powders; Preparations and properties; Cubic lattices; Temperature effect; Operating mode; Crystal defect; Experimental study; Gallium nitride; Powder; Inorganic compound; Characterization; Hexagonal lattices; Additive; Crystallites; Chemical preparation; Crystal growth from solutions; Nanocrystal; III-V semiconductors
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/cm9905592

Under ammonothermal conditions, cyclotrigallazane, [H2GaNH2]3, was converted to nanocrystalline GaN. The coherent length of the GaN product could be controlled by manipulating reaction time and temperature. Nanocrystalline GaN powders with average crystallite sizes of 3−17 nm were produced in the temperature range of 150−450 °C. Analysis of the powders by XRD and TEM indicated that the nanocrystals possessed a structure composed of a random arrangement of cubic and hexagonal close packed planes. The addition of NH4I to the reaction mixture resulted in the isolation of bulk samples of phase pure, cubic GaN at temperatures as low as 200 °C. The synthesis of the cubic phase was found to be temperature dependent, with mixtures of cubic and hexagonal GaN being produced at temperatures greater than 350 °C.