Relationship between nano-architectured Ti1−xCux thin film and electrical resistivity for resistance temperature detectors

Ti1−xCux thin films were produced by the glancing angle deposition technique (GLAD) for resistance temperature measurements. The deposition angle was fixed at α = 0° to growth columnar structures and α = 45° to growth zigzag structures. The Ti-to-Cu atomic concentration was tuned from 0 to 100 at.% of Cu in order to optimize the temperature coefficient of resistance (TCR) value. Increasing the amount of Cu in the Ti1−xCux thin films, the electrical conductivity was gradually changed from 4.35 to 7.87 × 105 Ω−1 m−1. After thermal “stabilization,” the zigzag structures of Ti1−xCux films induce strong variation of the thermosensitive response of the materials and exhibited a reversible resistivity versus temperature between 35 and 200 °C. The results reveal that the microstructure has an evident influence on the overall response of the films, leading to values of TCR of 8.73 × 10−3 °C−1 for pure copper films and of 4.38 × 10−3 °C−1 for a films of composition Ti0.49Cu0.51. These values are very close to the ones reported for the bulk platinum (3.93 × 10−3 °C−1), which is known to be one of the best material available for these kind of temperature-related applications. The non-existence of hysteresis in the electrical response of consecutive heating and cooling steps indicates the viability of these nanostructured zigzag materials to be used as thermosensitive sensors.Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013 and Project PTDC/EEI-SII/5582/2014. A. Ferreira and C. Lopes thanks the FCT for Grant SFRH/BPD/102402/2014 and SFRH/BD/103373/2014. The authors thank financial support from the Basque Government Industry Department under the ELKARTEK Programinfo:eu-repo/semantics/publishedVersio