Ni-Cu alloy films were deposited onto Mg0(001) substrates at 230°C by d.c. plasma sputtering at 2.7 kV and 8 mA in pure Ar gas using an Ni-10wt.%Cu alloy target. The deposition time was 15 or 30 min. A d.c. bias voltage Vs ranging from 0 to - 140 V was applied to the substrate during deposition. The structure, composition and electrical properties of the films were studied as a function of Vs using cross-sectional transmission electron microscopy (XTEM) and X-ray photoelectron spectroscopy (XPS), and measurements of the temperature coefficient of electrical resistance (TCR) from - 135 to - 15°C. The alloy films, which have the f.c.c. lattice of the components, are monocrystalline with the relationship Ni-Cu(001) ∥MgO(001) and Ni-Cu  ∥MgO unless Vsp = - 110 V. The Cu content in the films decreases from 8 wt.% to 3 wt.% as Vs increases from O to - 140 V. The growth rate of the films and the value of TCR η (η > 0) depend on Vs; the film thickness d for the films deposited for 30 min reaches 50±1 nm at Vs = 0 V and 74 ± 2 nm at Vs = - 140 V, while η for the films deposited for 30 min increases appreciably with increasing Vs compared with the films deposited for 15 min, although η is highest at Vs = - 140 V for both cases.
- Transmission electron microscopy (TEM)
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry