Effect of Mass Fraction of Ni in Solution on the Microstructure and Sensitivity of Cu/Ni Film as Low-Temperature Sensor

摘要

The purpose of this research is studying microstructure, the resistivity of Cu/Ni film produced by electroplating on the various mass fraction of Ni in the electrolyte. Then the film is tested for its performance as a temperature sensor. The electrolyte solution was made from mixing of NiSO_(4), NiCl_(2), H_(3)BO_(3), and H_(2)O. Plating was conducted on power 1.5 V and 60℃ bath temperature. The results showed deposits containing Ni and NiO. The X-ray diffraction parameters of Ni[111] and NiO[111] such as intensity, d-spacing and grain size on variations of Ni mass fraction in solution followed the parameters diffraction of Cu[111]. The resistivity is contributed by competition between those three diffraction parameters. Testing Cu/Ni films for sensing the temperature of liquid nitrogen (0℃ to -140℃) shows that all samples have exhibited their performance as low-temperature sensors. The temperature has a linear relationship to the output voltage of the sensor with the sensitivity ranging from 0.75′10~(-3) V/℃ to 1.05′10~(-3) V/℃. The highest sensitivity in accordance to the sample produced from 8.83 g Ni in the electrolyte.