Optical, Electrical and Structural Study of Mg/Ti Bilayer Thin Film for Hydrogen Storage Applications

Bilayer Mg/Ti (200 nm) thin films were successfully prepared by using D.C. magnetron sputtering unit. These films were vacuum annealed at 573 K temperature for one hour to obtain homogeneous and intermixed structure of bilayer. Hydrogenation of these thin film structures was made at different hydrogen pressure (15, 30 & 45 psi) for 30 min to visualize the effect of hydrogen on film structure. The UV–Vis absorption spectra, I-V characteristics and Raman spectroscopy were carried out to study the effect of hydrogen on optical, electrical and structural properties of Mg/Ti bilayer thin films. The annealed thin film represents the semiconductor nature with the conductivity of the order of 10-5 Ώ⁻¹-m⁻¹ and it decreases as hydrogen pressure increases. The nonlinear dependence of resistivity on hydrogen pressure reveals inhomogeneous distribution of hydrogen in the thin film. Raman spectroscopy confirmed the presence of hydrogen in thin film where the intensity of peaks was found to be decreased with hydrogen pressure.