61 MHz). The 12H NMR spectra were recorded in methylene chloride (Aldrich, Gold Label), and the solvent signal (5.32 ppm) due to 2H in natural abundance was used to calibrate the field.The infrared spectra of the coals (2-4%) in dry potassium bromide were recorded with a Nicolet 20 spectrometer. The pellets were dried in vacuo at 65 °C for 20 h before the spectra were recorded.

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Three samples of passivated ultrafine iron carbide particles, synthesized by laser induced pyrolysis of gaseous precursors, were examined by x-ray diffraction, x-ray photoelectron spectroscopy, and thermogravimetry/mass spectroscopy at temperatures as high as 600 °C under a He atmosphere. The approximate 6–7 nm diam particles began to sinter at temperatures between 300 and 400 °C and formed a complex mixture of carbide, oxide and metallic phases. Preservation of the carbide structure on heating was dependent on the purity of the carbide, and the concentration of oxygen and carbon in the particles. A topotactic transformation from Fe7C3 to Fe0.98O was observed and is discussed relative to the as-synthesized/passivated particles composition and structure. This topotaxy leads to the selective formation of γ-Fe2O3 from specific ultrafine particle carbides.

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Alloy films of Ni-Co and Ni-Cr of compositional ratios 1:1, 1:3, and 3:1 deposited by vapor deposition were studied by Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD). Results of TEM analysis on the Ni-Co alloy films indicated that the films were face-centered cubic (fee) in structure. XRD results confirmed the TEM observations. TEM analysis of Ni-Cr alloy films showed that the films were bodycentered cubic (bec) in structure. With increase in the Cr content more than 25%, the material contained a higher fraction of an amorphous phase. XRD studies provide limited information owing to the quasi-amorphous structure of the films of high Cr content.