Gradient palladium-yttrium hydrogen-permeating composite film material and preparation method thereof

Abstract

The invention discloses a gradient palladium-yttrium hydrogen-permeating composite film material and a preparation method thereof. The preparation method takes a commercial copper foil or soda-lime glass as a substrate, a high-purity palladium target and a high-purity yttrium target as sputtering materials, and high vacuum multi-target magnetron sputtering equipment as a preparation tool, and by fixing the target position sputtering power of the yttrium target, changing the target position sputtering power of the palladium target in a co-sputtering deposition process, the adjustment on the yttrium and palladium relative content in the film material is achieved, and the thickness of the prepared film is controlled by changing the co-sputtering time, so that the palladium-yttrium hydrogen-permeating composite film material with the changeable thickness is prepared finally. The preparation method has the characteristics that the preparation flow is short, the operation is simple, the parameter control range is wide, the implementation is easy, the gradient layer thickness and palladium and yttrium relative content can be flexibly controlled, and the preparation method has good commercial prospects.

Description

technical field [0001] The invention relates to the field of preparation of gradient thin film materials, in particular to a gradient palladium yttrium hydrogen permeable composite thin film material and a method for preparing the thin film material by high-vacuum double-target magnetron sputtering. Background technique [0002] Palladium has excellent hydrogen-sensing properties, and is often used as the hydrogen-sensing layer of hydrogen-sensing sensors, and most of the hydrogen-sensing elements currently use this metal. by Pd-H 2 It can be seen from the phase diagram of the system that below 300 °C, palladium exists in two forms: α phase and β phase. In the absence of hydrogen, palladium always exists in the form of α-hydrogen-poor phase; but when the hydrogen content in palladium exceeds the limit of hydrogen absorption of α-phase palladium, palladium will undergo a phase transition, from α-hydrogen-poor phase into a β-hydrogen-rich phase. Both the α-hydrogen-poor pha...

AI Technical Summary

Problems solved by technology

Both the α-hydrogen-poor phase and the β-hydrogen-rich phase are face-centered cubic lattices, but the lattice constant of the β-hydrogen-rich phase will increase (the lattice constant will increase by 3.5% in pure hydrogen), resulting in the existence of a palladium layer Defects such as poor adhesion and high brittleness are the so-called "hydrogen embrittlement", which significantly affects the hydrogen permeability of pure palladium membranes

However, since the thickness of the palladium film is generally around 50-100 μm, it cannot maintain sufficient stability and mechanical strength if it is too thin, and it will greatly increase the cost and reduce the hydrogen permeability of the film if it is too thick.