Cubic ͑3C͒ silicon carbide ͑SiC͒ epilayers grown on Si substrates by chemical vapor deposition, characterized using transmission electron microscopy ͑TEM͒, high-resolution x-ray diffraction ͑HRXRD͒, and Raman spectroscopy, reveal the presence of biaxial in-plane strain. Defect ͑stacking faults, twins, dislocations͒ distributions revealed by TEM are correlated with peak widths obtained from HRXRD measurements and Raman shifts of the zone center longitudinal optical phonon line. TEM showed defect densities decreasing with increasing distance from SiC / Si interface as the lattice mismatch stress is relaxed. Structural defect densities show the most significant reduction within the first 2 m of the epilayer. TEM observations were correlated with a monotonic decrease in HRXRD peak width ͑full width at half maximum͒ from 780 arc sec ͑1.5 m thick epilayer͒ to 350 arc sec ͑10 m thick epilayer͒. Raman spectroscopy indicates that the residual biaxial in-plane strain decreases with increasing epilayer thickness initially, but becomes essentially constant between 6 and 10 m. Differences in the observed behavior between HRXRD and Raman spectroscopy are discussed in terms of the fundamental interactions of incident radiation with the 3C-SiC epilayers.

White-colored materials synthesized by a thermal annealing of milled GaN powders at 930 °C in a nitrogen atmosphere were identified to be monoclinic β-Ga2O3 nanowires by x-ray diffraction and scanning electron microscopy. High-resolution transmission electron microscopy revealed that these nanowires are single nanocrystals, and energy dispersive x-ray indicated that these nanomaterials are free of any metals. In addition, bundles of these crystalline nanowires in the rectangular-pole shape are a few centimeters in length.