Aluminum nitride flakes and spheres

摘要

Methods are described for preparing aluminum nitride of controllable morphology for ceramic and heat conduction applications. The methods comprise forming spherical particles or flakes of an intermediate, RA1NH, followed by heating the spheres or flakes of RA1NH at elevated temperatures to produce high purity aluminum nitride of corresponding morphology. Spheres of RA1NH are formed by (i) freezing a suspension of RA1NH in a liquid medium and thawing, by (ii) aging the suspension, or by (iii) dissolving RA1NH in a liquid medium and precipitating it. Flakes are formed by freezing a suspension of RAINH in a liquid medium and removing frozen medium from the frozen suspension.