Investigation of a copper–nickel alloy resistor using co-electrodeposition

Abstract: Using this co-electrodeposition method, we successfully prepared a Cu–Ni alloy film at a low temperature. The results of this study showed that when Cu–Ni film is co-deposited at − 1.3 V (vs. Ag/AgCl) in a solution with a composition ratio of Ni to Cu ions of 90:10, the atomic percentage of Cu to Ni necessary to form the Cu–Ni alloy is approximately one. Electroplated for 20 min, the thickness of the Cu–Ni film grows to around 10 μm, and the resistance is approximately 103 mΩ. In this work, the samples were annealed at 700, 800, and 900 °C for 30 min, respectively. The resistance increased gradually with increases in the annealing temperature because of the increasing entropy of the Cu–Ni alloy. On the contrary, the TCR decreased gradually with increases in the annealing temperature. The sample annealed at 900 °C exhibited a single crystal FCC Cu–Ni alloy with a lattice constant of 3.62 Å, corresponding to a very low TCR of around 50 ppm/ °C. Graphic Abstract: [Figure not available: see fulltext.].