Articles you may be interested inResistivity change of the diamondlike carbon, deposited by focused-ion-beam chemical vapor deposition, induced by the annealing treatment Iron oxide thin films prepared by ion beam induced chemical vapor deposition: Structural characterization by infrared spectroscopy This work presents results from the characterization of ion-assisted chemical vapor deposition of platinum from trimethyl-methylcyclopentadienyl-platinum ͑C 9 H 16 Pt͒. Films were deposited in squares ranging from 50 to 200 m on a side using a focused ion beam system. The effects of Ga ϩ ion flux and precursor flux on the deposited films' composition and resistivity were determined. Films were characterized using atomic force microscopy, Rutherford backscattering spectrometry, and Auger electron spectroscopy. Results show that increasing precursor flux at constant ion flux increases Pt and C, but decreases Ga content of the film. Increasing ion flux at constant precursor flux increases Pt content, while decreasing C content of the films. Resistivity did not depend on the thickness of 50-200 nm thick films. Resistivity was shown to follow C content, with films with lower C content having lower resistivity.

Neutron-irradiated vanadium alloys were evaluated for their susceptibility to irradiation hardening, helium embrittlement, swelling, and residual radioactivity, and the results were compared with those for the austenitic and ferritic stainless steels. The VANSTAR-7 and V-15Cr-5T± alloys showed the greatest hardening between 400 and 600°C while V-3Ti-ISi and V-20Ti had lower values that were comparable to those of ferritic steels. The V-15Cr-5Ti and VANSTAR-7 alloys were susceptible to helium embrittlament caused by the combination of weakened grain boundaries and irradiation-hardened grain matrices. Specimen fractures were entirely intergranular in the most severe instances of embrittlement. The V-3Ti-ISi and V-20Ti alloys were more resistant to helium embrittlement. Except for VANSTAR-7 irradiated to 40 dpa at 520°C, all of the vanadium alloys exhibited low swelling that was similar to the ferritic steels. Swelling was greater in specimens that were preimplanted with helium using the tritium, trick. The vanadium alloys clearly exhibit lower residual radioactivity after irradiation than the ferrous alloys.

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Specimens of V-15Cr-5Ti, VANSTAR-7, and V-3Ti-ISi were encapsulated in TZM tubes containing 7 Li to prevent interstitial pickup and irradiated in FFTF (MOTA experiment) to a damage level of 40 dpa. The irradiation temperatures were 420, 520, and 600°C. For a better simulation of fusion reactor conditions, helium was preimplanted in some specimens using a modified version of the "tritium trick." The V-15Cr-5Ti alloy was most susceptible to irradiation hardening and helium embrittlement, followed by VANSTAR-7 and V-3Ti-ISi. VANSTAR-7 exhibited a relatively high maximum void swelling of ~6£ at 520°C while V-15Cr-5Ti and V-3Ti-ISi had values of less than 0.3% at all three temperatures. The V-3Ti-ISr clearly outperformed the other two vanadium alloys in resisting the effects of neutron irradiation.

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B x Ga 1-x N films were deposited on 6H-SiC (0001) substrates at 1000°C by low pressure MOVPE using diborane, trimethylgallium, and ammonia as precursors. The presence of boron was detected by Auger scanning microprobe, the shift of the (00.2) x-ray diffraction peak, and low-temperature photoluminescence. A single-phase B x Ga 1-x N alloy with x = 1.5% was produced at the gas phase B/Ga ratio of 0.005. Phase separation into wurtzite BGaN and the B-rich phase occurred for a B/Ga ratio in the 0.01-0.2 range. Only BN was formed for B/Ga > 0.2. The B-rich phase was identified as h-BN with sp 2 bonding based on the results of Fourier transform infrared spectroscopy. As the diborane flow exceeds the threshold concentration, the growth rate of BGaN decreases sharply, because the growth of GaN is poisoned by the formation of the slow growing BN phase. The bandedge emission of B x Ga 1-x N varies from 3.451 eV for x = 0% with FWHM of 39.2 meV to 3.465 eV for x = 1.5% with FWHM of 35.1 meV. The narrower FWHM indicates that the quality of GaN epilayer is improved with a small amount of boron incorporation. The PL linewidths become broader as more boron is introduced into the solid solution.

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