Spectroscopic Characterization of Rocksalt-Type Aluminum Nitride

Starting from nanocrystalline and submicron wurtzite-aluminum nitride (w-AlN) powder rocksalt structure (rs-AlN) samples were synthesized by two different methods of shock wave recovery experiments. The resulting samples contained up to 86% rs-AlN, stable at room temperature, giving for the first time the possibility to comprehensively characterize the material by powder X-ray diffraction, Fourier transform infrared (IR), Raman, and Al-27 NMR spectroscopy. Raman and IR modes were calculated by density functional theory, allowing for the interpretation of the respective experimental spectra. By Al-27 NMR the chemical shift of rs-AlN was determined, and the quadrupolar coupling constant was estimated.