NOVEL METHODS FOR DEPOSITION OF BORON CARBIDE FILMS

By combining pentaborane (B5H9) and decarborane (B10H14) with methane in a plasma reactor, a variety of boron-carbides can be made over a wide range of compositions. The resulting thin films have uniform composition and appear to be polycrystalline

Excited-state properties of trans-(9-anthryl)ethylenes. Effects of geometric distortion about single bond

The singlet- and triplet-related photophysical properties of four trans-1,2-diarylethylenes, containing methyl, phenyl, 1-naphthyl, and 9-anthryl group as one substituent and 9-anthryl group as the other, have been studied by steady-state and time-correlated fluorescence measurements, laser flash photolysis, and pulse radiolysis. The results show pronounced effects of the photoexcitation-induced geometric distortion (about the anthryl-to-ethylene "single" bond) in rendering fluorescence and triplet-triplet absorption spectra broad and structureless, and in enhancing radiationless processes from singlets, triplets, and exciplexes (with N,N-dimethylaniline). The shortening of triplet lifetimes, and the triplet quenching behaviors toward ferrocene, di-tert-butylnitroxy radical, and oxygen, are also explainable in terms of the torsional relaxation; these effects are similar to, but less pronounced than, those arising from double bond twisting in smaller arylethylene triplets. No photophysical anomaly attributable to ground-state rotamerism is observed in fluid solutions

Fabrication of ferromagnetic and antiferromagnetic chromium oxides by organometallic chemical vapor deposition

We have been able to fabricate CrO2 and Cr2O3 from ultraviolet photolytic and plasma-assisted decomposition of Cr(CO) 6 in an oxygen carrier gas. The composition of these films is uniform in composition and contains little contamination. Using magneto-optic Kerr effect measurements, we have been able to demonstrate that the CrO2 films are ferromagnetic