Tuning of the martensitic transformation temperature in Cu–Zn thin films by control of zinc vapor pressure during annealing

We report a shape memory effect in Cu–Zn thin films grown by electrodeposition on pyrolytic graphite from pyrophosphate-based electrolytes. Cu–Zn films showing a martensitic transformation could only be obtained after the optimization of thermal annealing parameters such as annealing temperature, Zn vapour pressure and fast quenching. By means of controlling the Zn vapour pressure during annealing using a bulk reference Cu–Zn alloy, the chemical composition of the films could be adjusted and the martensitic transformation temperatures of the films could be tuned.