[en] By using a longitudinal static magnetic field, the authors have show that it is possible to excite an intensive plasma in a simple stainless steel tube which is connected with a RF power supply. Under certain conditions, the very bright Ar II lines were excited. The emission intensities of Ar II lines were increased with the increasing in RF power, magnetic field, and the decrease in argon pressure. As the plasma-sheath boundary oscillating under the RF voltage, the plasma column is periodically compressed by the oscillating boundary

[en] X spectrum processing method based on AR model was proposed. The method looks the measured X spectrum as the classic spectrum estimation of a signal. Then using FFT calculates the signal's self-correlation function, and adopting AR model re-estimates the X spectrum. After processing, the spectrum becomes smoother and the resolution of the spectrum has been enhanced. The efficiency of the method has been verified by experiment result. (authors)

[en] Ultrafine amorphous FeNiB powder has been prepared by borohydride reduction by mixing the aqueous solutions. The influence of the mixing way and the drying procedure was observed. The paramagnetic doublet component of the Moessbauer spectra indicates the existence of the Fe³⁺, whose state was discussed. The Moessbauer measurements have been performed at room temperature (RT) and at 77 K. The effect of the magnetic fields on the amorphous powders was somewhat analogous to that on amorphous ribbons produced by a melt spinning method. The spontaneous magnetization of the flaky powder sample tended to locate on the sample plane. (orig.)

[en] In this work, results on the study of the structure and photoluminescence (PL) properties of SiO_xN_y thin films are presented. The films were deposited at room temperature using a dual-ion-beam co-sputtering system. The XRD and TEM results show that the deposited films have an amorphous structure. In the XPS results, authors find N 1s spectra consist of one symmetric single peak at 397.8 eV, indicating that the nitrogen atoms are mainly bonded to silicon. It is in agreement to the result of FTIR. In SiO_xN_y films, an intense single PL peak at 590 nm is observed. Furthermore, with the increase of the N content in the SiO_xN_y films, the intensity of the PL peak at 590 nm increases a lot. The PL peak of 590 nm is suggested to originate from N-related defects. (author)

[en] In pulsed-controlled grid traveling wave tubes, electrons are emitted from the Mo grid heated by the hot cathode and contaminated by the evaporation material (i.e. BaO or Ba) from the cathode, which may cause the tubes to be unavailable. Some studies show that carbon film coated on a Mo grid can effectively suppress the grid emission. The reasons for it, however, have not been well understood. To study the effect of carbon film on the Mo grid contaminated with BaO or Ba under high temperature, carbon films were prepared on the Mo substrates at room temperature by dual ion beam sputtering deposition system and post-annealing was conducted to know their status under high temperature, and BaO layer was coated on the Mo and carbon-coated Mo substrates by the chemical method in our experiments. The compositional and phase change of BaO/C/Mo is investigated at two different temperatures of 973 and 1223 K. The results show that the BaO/C/Mo system changes into the C/Mo after the exhaustion of BaO in the case of 1223 K owing to the reaction of carbon with BaO, however, the BaO/C/Mo is almost invariable at 973 K. The mechanism that the addition of carbon film can effectively suppress the grid emission under its working conditions is discussed according to the experimental results and the calculation of the reaction free energy

[en] Dry etching of 6H silicon carbide (6H-SiC) wafers in a C₄F₈/Ar dual-frequency capacitively coupled plasma (DF-CCP) was investigated. Atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) were used to measure the SiC surface structure and compositions, respectively. Optical emission spectroscopy (OES) was used to measure the relative concentration of F radicals in the plasma. It was found that the roughness of the etched SiC surface and the etching rate are directly related to the power of low-frequency (LF) source. At lower LF power, a smaller surface roughness and a lower etching rate are obtained due to weak bombardment of low energy ions on the SiC wafers. At higher LF power the etching rate can be efficiently increased, but the surface roughness increases too. Compared with other plasma dry etching methods, the DF-CCP can effectively inhibit C_xF_y films' deposition, and reduce surface residues

[en] The silicon-rich silica films were prepared by a dual-ion-beam co-sputtering method from a composite target in an argon atmosphere. The structure of the films studied by the aid of TEM and XRD is amorphous. The photoluminescence (PL) spectra were found to have a 4-luminescent band peak at 320 nm, 410 nm, 560 nm, and 630 nm, respectively, at rom temperature. The intensity and the wavelength position of PL are dependent on annealing temperature (Ta), and the luminescent mechanism is analyzed

[en] Ab initio natural hybridized orbital method with STO-3G basis set has been applied to study nuclear spin-spin coupling constants of C-P bonds, by which a general equation has been set up. Furthermore, three compounds have been chosen to test the equation, and the results are in basically agreement with the experimental values

[en] The nanometer-size crystalline Ti film have been manufactured by using of a sputtering deposition utilising Electron Cyclotron Resonance (ECR) plasma at room temperature. The substrates are quartz glass, NaCl monocrystal and pure Al. Thee structure and the composition of the Ti films have been determined by using XRD, TEM, XPS. The results show that the size d < 10 nm, and with a stable abnormal fcc structure. The influence of working parameters on the crystal structure, the grain size, deposition rate and adhesion of the films have been studied systematically. The mechanism of depositing Ti films have been discussed

[en] Fe-N films were prepared on Si substrate by dual ion beam sputtering (DIBS). It is found that the crystal structure of the films varies from α-Fe, to ε-Fe_2-3N, ε-Fe_2-3N + γ'-Fe₄N, and finally γ' -Fe₄N with the increase in substrate temperature (Ts). The magnetic properties of the films were investigated by a vibrating sample magnetometer (VSM). The structure of the films is insensitive to the ratios of N₂/Ar in main ion source (MIS), and is mainly influenced by the substrate temperature (Ts)