The relaxation processes in the Al-(Nb, Mo, Ta, W) binary amorphous thin films

Structural relaxation and crystallization of Al-(Nb, Mo, Ta, W) amorphous thin films under isochronal condition were examined by continuous in situ electrical resistance measurements in vacuum. The amorphous Al-early transition metals (TE) thin films were prepared by simultaneous sputtering from two independently controlled DC magnetron sources in the CMS 18 deposition device. The structure of the as-deposited, heat-treated, and crystallized films was investigated by the XRD method. The dynamical crystallization temperature was estimated from the rapid change of the derivative of resistivity vs. temperature curve (dρ/dT). For the isochronal heating, it was observed that the relaxation effects decreased with an increase of the heating rate and decreased with the content of early transition metal in the film. Assuming the linear dependence of resistivity with temperature (Δρ/ρRT = αΔT) in the observed temperature interval the linear ρ(T) dependence is extracted from the relaxation effects. Adopted experimental function of ρ(T) is fitted to a modified Bloch–Grüneisen formula. Excellent agreement of experimental data and fitting function is obtained.

► We examine structural relaxation of the Al-(Nb, Mo, Ta, W) amorphous thin films.
► Adopted Bloch–Grüneisen formula is used to find best fit function.
► Relaxation effects decreased with the content of early transition metal in the film.