Electrons Extraction from MWCNT/PEO Composites

Electron field emission was investigated from multi-walled carbon nanotubes (MWCNT)/polyethylene oxide (PEO) composites with (5, 15, 25, 33, 40 and 50wt.% of MWCNTs). The resulted samples were characterized using Raman spectroscopy to estimate The MWCNTs-PEO (Nanotubes-Polymer) interaction through the shifting or width alteration of the peaks. The SEM micrographs were issued to investigate the surface morphology of the samples. In addition, and in order to gain additional understanding of the filler content and the samples thermal stability; the TGA technique was applied. The current density versus applied electric field J(E) and current stability of the prepared composites were measured using a range of voltages. Here, the 33wt.% composite displayed the lowest turn on field of 6.51V/μm, whereas the highest current density achieved was 1.17mA/cm2 by the 40wt.% composite

Sputtering power and deposition pressure effects on the electrical and structural properties of copper thin films

We investigated the effects of sputtering power and deposition pressure on the electrical and structural properties of dc magnetron sputter-deposited copper films on p-type silicon grown at room temperature. Results from our experiments showed that the deposition rate of the copper films increased proportionally with the sputtering power. Sputtering power also affected the structural properties of the copper films through the surface diffusion mechanism of the adatom. From the scanning electron microscopy surface analysis, the high sputtering power favored the formation of continuous film. The poor microstructure with voided boundaries as a result of low sputtering power deposition was manifested with the high resistivity obtained. The deposition rate was found also depending on the deposition pressure. The deposition pressure had the contrary effect on structural properties of copper films in which high deposition pressure favored the formation of voided boundaries film structure due to the shadowing effect, which varied with different deposition pressure. (c) 2005 Springer Science + Business Media, Inc