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  • Author: A. Kuzmin x
  • Technical and Applied Physics x
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Study of Copper Nitride Thin Film Structure

Abstract

X-ray diffraction and x-ray absorption spectroscopy at the Cu K-edge were used to study the atomic structure in copper nitride (Cu3N) thin films. Textured nanocrystalline films are obtained upon dc magnetron sputtering on substrates heated at about 190 °C, whereas amorphous films having strongly disordered structure already in the second coordination shell of copper are deposited in the absence of heating.

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Influence of Pressure and Temperature on X-Ray Induced Photoreduction of Nanocrystalline CuO

Abstract

X-ray absorption spectroscopy at the Cu K-edge is used to study X-ray induced photoreduction of copper oxide to metallic copper. Although no photoreduction has been observed in microcrystalline copper oxide, we have found that the photoreduction kinetics of nanocrystalline CuO depends on the crystallite size, temperature and pressure. The rate of photoreduction increases for smaller nanoparticles but decreases at low temperature and higher pressure.

Open access
PATTERNED LASER CRYSTALLIZATION OF a-Si

PATTERNED LASER CRYSTALLIZATION OF a-Si

Thin films of amorphous Si on glass were crystallized by pulsed nano- and picosecond lasers. Two methods for creating the desired patterns of crystallized regions were used. In the former, the pattern is produced by a focused laser beam, and in the latter it is made using a prefabricated mask. The electric conductivity of crystallized films increases by more than 4 orders of magnitude in comparison with untreated amorphous films.

Open access
Magnon and Phonon Excitations in Nanosized NiO

Abstract

Single-crystal, microcrystalline and nanocrystalline nickel oxides (NiO) have been studied by Raman spectroscopy. A new band at ~200 cm−1 and TO-LO splitting of the band at 350–650 cm−1 have been found in the spectra of single-crystals NiO(100), NiO(110) and NiO(111). The Raman spectra of microcrystalline (1500 nm) and nanocrystalline (13–100 nm) NiO resemble those of the single crystals. They all contain the two-magnon band at 1500 cm−1, indicating that the oxides remain at room temperature in the antiferromagnetic phase. Besides, a new sharp Raman band has been observed at 500 cm−1 in nanocrystalline NiO. Its temperature dependence suggests the magnetic origin of the band, possibly associated with the one-phonon–one-magnon excitation at the Brillouin zone centre.

Open access