V. I. Rubtsov

EELS, XPS and IR study of C60·2S8 compound

Abstract Results from electron energy loss, X-ray photoelectron, and infrared spectroscopies are ptesented for the C 60 ·2S 8 compound. As one goes from C 60 to C 60 ·2S 8 , binding energy decreases by 0.5 eV, and ( σ + π ) plasmon energy decreases by 1.2 eV. Arguments for charge redistribution are performed.

Reflection electron energy-loss spectra of the fullerenes C60 and C70

High purity polycrystalline samples of C60 and C70 were obtained and studied by the electron energy-loss spectroscopy in the reflection mode. The spectra were used for determination of the loss functions of fullerenes. Loss functions of the fullerenes were compared with those of graphite. It was established that the relative intensities of the peaks corresponding to (σ+π)- and π-plasmons depended on the primary electron energy, while the (σ+π)-plasmon energies did not depend on the primary electron energy and were equal to 25.0 eV for C60 and 24.8 eV for C70. The conclusion on the space localization for plasma occilations in fullerenes was made on the base of the study of the energy dependent loss functions.

Electron energy-loss spectroscopy as an analytical tool in the study of TiSi2/Si interfaces

Abstract Electron energy-loss spectra have been recorded for Ti, Si and TiSi 2 with E p = 100, 400 and 2000 eV. It is shown that the spectra may be used for the identification of compounds in the TiSi 2 /Si planar structure with thickness less than 0.4 nm.

Low-temperature silicon nitride: a promising dielectric in semiconductor technology

Abstract We obtained thin dielectric solid films of SiNx:H on Si(100). The deposition was carried out from a gas mixture of SiH4NH3N2 using an r.f. plasma discharge (450 kHz) at 293

Auger emission of valence band and local electronic structure of niobium carbonitride

Partial substitution of nitrogen by carbon in the metalloid sublattice of NbN possessing the NaCl structure leads to an increase in the temperature of the transition to the superconducting state. The changes in the local density of states on formation of NbCxN1-x alloys, which may be related to this increase, were investigated by Auger electron spectroscopy. The NbM5N2,3V, NbM5VV, CKVV and NKVV Auger spectra for NbCxN1-x over the range 0.06<x<0.90 were obtained. The interpretation of the line shape is based on the results of the band structure calculations. It was shown that the effective hole-hole interaction energies, Uef, in the valence band on metal sites are negligible compared with those on metalloid ones. Furthermore, localization of two-hole C2p states depends on the carbonitride composition and Uef has a peculiarity at an x value of about 0.2.

Electron spectroscopy study of (ET)2C60 compound

Abstract Results of X-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS) studies are presented for the (ET) 2 C 60 compound. It was established that XPS data correspond to small value of charge transfer in the complex. Loss function of (ET) 2 C 60 was extracted from EEL spectra. Energy of main ( σ + π ) plasmon h ω=23.8 eV was determined.

STUDY OF C60.2S8 BY THE METHODS OF INDUCED ELECTRON EMISSION

It was shown by the methods of induced electron emission that a transfer of the electron density from C60 molecules to the eight-membered ring of sulfur is characteristic of C60·2S8. The value of the (σ+π)-plasmon energy for C60·2S8 is approximately 1 eV less than that for pure C60. In a high vacuum, the C60·28 surface is depleted in sulfur.

The loss functions of fullerenes C60 and C70 and graphite-like materials

Abstract High purity polycrystalline samples of C 60 and C 70 were obtained and studied by the electron energy-loss spectroscopy. The spectra in the reflection mode were used to determine the loss functions of fullerenes. It was established that the energies of ( σ + π )- and π-plasmons are equal to 25.2 and 5.8 eV for C 60 and 24.8 and 5.7 eV for C 70 . Loss functions of the fullerenes were compared with those of graphite and glassy carbon.

Preparation and investigation of the crystals formed in the buckminsterfullerene-tetraselenotetracene-carbon disulfide system

Crystals containing up to 30 wt. % CS2, according to the data of IR and X-ray photoelectron spectroscopy, were isolated from the C60-TSeT-CS2 (TSeT is tetraselenotetracene) system. The unusually high concentration of carbon disulfide results in the complete sublimation of the crystals at a relatively high temperature (520 °C). The electron energy loss spectra of the crystals obtained were measured and analyzed.

X-RAY PHOTOELECTRON SPECTRA OF RH(III) TRIFLUOROACETATE

A study was made of the x-ray photoelectron spectra of Rh(I) and Rh(III) trifluoroacetate complexes. It was shown by using the Cls bond energies of the carboxylate carbon atom as a basis that bridging and monodentate coordination of the trifluoroacetate group could be distinguished with high resolution.