Synthesis and characterization of a nanostructured gallium nitride-PMMA composite

Nanostructured gallium nitride (GaN) has been prepared by the decomposition of a dimeric precursor, Ga₂[N(CH₃)₂]₆. The resulting greyish solid exhibited X-ray diffraction peaks at 20 = 35.5, 58 and 69°, corresponding, respectively, to the (111), (220), and (311) lattice planes of face-centred cubic (zinc blende) GaN. HRTEM showed that the material was fee, with numerous stacking faults. The GaN consisted of primary domains of diameter 5 nm agglomerated into large secondary particles, which were de-agglomerated using sonication. This process yielded single-crystal particles, which were dispersed in poly(methyl methacryate) (PMMA). The particle size was 5.5 ± 2.6 nm and the loading was approximately 9 mg ml^-1 The composites have a strong optical resonance in the blue region, at ca. 320 nm.