Growth and band gap of the filled tetrahedral semiconductor LiMgN

The cubic AIN-like compound, LiMgN, can be considered as a zinc blende-like (MgN)(-) lattice partially filled with He-like Li+ interstitials. LiMgN was synthesized by direct reaction between N-2 and LiMg alloy at around 800degreesC for 8 h. Polycrystalline crystals are grown as cornflake-like shapes with a light yellow color and show the LiMgN-phase (the lattice constant a = 4.955+/-0.005 Angstrom) except for non-reactant LiMg and oxide (LiNO3). The ordered structure between Li and Mg is not confirmed exactly by X-ray diffraction studies. The band gap of as-grown crystals evaluated using photoacoustic spectroscopy is 3.2 eV, which value is supported by an optical transmission spectrum. The band gap value of LiMgN is close to that of GaN (zinc blende, E-g = 3.45 eV). (C) 2002 Elsevier Science B.V. All rights reserved.