The fabrication of TiNi thin films by pulsed-laser deposition

Abstract

TiNi shape memory alloy (SMA) thin films have been fabricated by pulsed-laser deposition (PLD) at different substrate temperatures. The stoichiometry, surface morphology and crystallinity of the films were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM) and X-ray diffraction (XRD). The transformation behaviour and crystallization temperatures were investigated by differential scanning calorimetry (DSC). It is found that the Ni content of the deposited films ranges from 46.7 to 52.0 at.%. The films deposited at low temperature are amorphous. The crystallization temperature of the Ti-51.5 at.% Ni thin film is 449°C. The martensitic transformation temperature of the film is -20.8°C.