Comparison of NiTi thin films sputtered from separate elemental targets and Ti-rich alloy targets

• NiTi SMA thin films deposited by Co-sputtering of separate elemental targets.
• NiTi SMA thin films deposited by sputtering of Ti-rich alloy targets.
• Employing Ti-rich alloy targets leads to faster formation of crystallized NiTi coatings.
• More homogeneity in microstructure of NiTi coatings sputtered from alloy targets.

The kind of sputtering targets can adversely affect the microstructure, phase transformation behavior, mechanical and tribological properties of near equi-atomic NiTi thin films. This new finding was systematically investigated by employing comprehensive characterization and analysis techniques, including X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), differential scanning calorimetry (DSC), nanoindentation, ball-on-disc, and three dimensional (3D) optical microscopy.