Electrical transport properties of AlAs under compression: reversible boundary effect

The grain boundary effect can be modulated by compression and plays positive roles on performance of devices such as increasing the resistance difference between two states.

The relationship between surface treatments and corrosion resistance of hot-dip galvanized steel

In this work three surface treatments such as: polishing, sand-blast and polishedoxidized have been carried out on the hot-dip galvanized coatings. The roughness and corrosion resistance of coatings have been studied. Surface morphology of coatings has evaluated by scanning electron microscope (SEM). Corrosion behavior was analyzed by salt spray cabinet test and Tafel extrapolation test. The results showed that the sample under sand-blasted treatment exhibited the highest roughness number. Tafel polarization and salt spray cabinet tests reveal the sample with great roughness number have weak corrosion resistance. Difference observed in corrosion behaviour can be explained by difference in surface roughness.

The Dependence of Aluminum/Tungsten Reaction on Crystalline Phases of Cvd Tungsten

ABSTRACTThe reaction between Al and CVD-W films has been studied. Al/α-W/Si and Al/β-W/Si structures were prepared by deposition on different Si substrates by changing deposition conditions using silane reduction of tungsten hexafluoride, followed by Al-Si-Cu alloy film sputter deposition. The sheet resistance of Al/α-W/Si structure is higher than that of Al/β-W/Si structure after 500°C annealing. RBS measurements show that the W diffusion into Al occurs in both structures after annealing, and the reaction between α-W and Al takes place easily compared with that between β-W and Al. This causes the sheet resistance difference. The activation energies for the W diffusion into Al, however, are almost the same in both structures. When CVD-W films are exposed to air after removal from the reactor, the sheet resistance of β-W film increases according to the exposure time, while that of α-W film does not. AES measurements indicate that the β-W film absorbs more oxygen than the α-W because of the difference of grain structures. The resistance increase of β-W film is caused by the oxygen that is absorbed from air. Our results indicate that the oxygen in the β-W layer suppresses the W diffusion into Al. Once the reaction begins, however, the diffusion into Al does not depend on crystalline phases of CVD-W.