Carbon nitride films with the composition ratio CR(C/N)=0.5–3.0 were prepared by the ion and vapor deposition method, where carbon was evaporated on various substrates while being simultaneously bombarded with 0.5–10.0 keV nitrogen ions. The properties of the films were studied by x-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectrometry (FT-IR), ultraviolet transmission spectroscopy, x-ray diffraction, and hardness measurements. The films formed at energies lower than 0.8 keV and CR(C/N)=0.6–0.7 on tungsten carbide showed the highest Knoop harness of 6400 kgf/mm2 on films with 1 μm thickness and a maximum optical band gap of 2.7 eV. X-ray diffraction measurements demonstrated that all films have an amorphous structure. The XPS and FT-IR studies indicated that the peak newly observed at 286.3 eV in the C-1s1/2 XPS spectra arises from triple bonding C≡N.
The connection between electron channeling and electron diffraction is discussed on the basis of the dynamical theory. Results of the many-beam calculations for 50 keV to 2 MeV electrons incident almost parallel to a [110] axis of a MgO crystal are used as examples. Bloch waves with a marked concentration of electron density at rows of atoms are obtained, and interpreted as states of electrons bound to the rows of atoms, corresponding to the classical picture of channeling. This can be shown properly by applying the tight-binding method of band theory in the two dimensions perpendicular to the axis. In this picture the "rosette motions"' in the classical theory are interpreted as p-tvpe, d-type, etc. Bloch waves, and the "weavons" as loosely-bound s-type Bloch waves. They are connected to the pictures of the Borrmann effect and the Bloch-wave channeling in the diffraction theory.
The hydrogen content in a-SiC:H films prepared by the plasma decomposition of gas mixtures of silane and methane or ethylene was measured by 1H(15N, αγ)12C nuclear reaction (NR) and infrared absorption spectroscopy (IR). The contents observed by both methods can be made to agree well for most of the films by putting the average value of the inverse absorption cross section for the CH
n
(n=1, 2 and 3) stretching mode over all values of n as A
s=1.0×1021 cm-2. In some films prepared from silane and ethylene mixtures, the hydrogen content given by NR was higher than that by IR. Hydrogen release from films with a hydrogen content of over 30 atm.% was observed during NR analysis. The mechanism of the hydrogen release is discussed by comparing the IR spectra before and after ion bombardment.
The variation with crystal thickness of the crystal structure images in electron microscopy is discussed in the case of an ideal objective lens and a crystal with a simple lattice. For small values of the interaction parameter, which represents the interaction between the incident electron and the crystal potential, the image changes periodically. Especially, the periodicity holds strictly for a definite value of the interaction parameter. For large values of the interaction parameter, the image of an atomic string consists of a strong center spot and one or more rings and the relative intensity of the spot and rings varies in a complicated way with the thickness. Effects of the objective aperture and the absorption on crystal structure images are also discussed.
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