Hydrogen in obliquely deposited LaNi5 thin films

During the last decade, thin film metal hydride has become an emerging field of research. The effect of hydrogen charging/discharging on the electrical resistance of obliquely deposited (θ=0°,30°,45°,60°,75°) LaNi_5 thin films of thickness 130±0.5 nm was investigated. It was found that the activation of LaNi_5 thin films for hydrogen absorption is fairly simple. The change in resistance due to hydrogen absorption increases with the angle of deposition and decreases with desorption of hydrogen. Thin films deposited at large angle absorb more hydrogen than low angle deposited LaNi_5 films. This is due to the structure variation in these thin films as a result of “self-shadowing effect”. Hydrogen absorption/desorption is also fast for films deposited at higher angles.