Tailoring the multifunctional properties of Ni80Ce20 thin films through deposition thickness and annealing temperature for advanced device applications

This study examines the influence of deposition thickness and annealing temperature on the surface roughness, surface energy, and mechanical, electrical, and magnetic properties of Ni80Ce20 thin films deposited on Si(100) substrates. Atomic force microscopy (AFM) revealed a reduction in the arithmetic mean surface roughness (Ra) from 1.23 nm in the as-deposited state to 0.97 nm after annealing at 300 °C, accompanied by a decrease in surface energy from 43.0 to 25.2 mJ/mm2 for 10 nm films. Hardness measurements showed a maximum value of 14.39 GPa for the 30 nm film annealed at 300 °C, while the lowest hardness, 9.66 GPa, was observed in the as-deposited 50 nm film. Electrical resistivity decreased with increasing film thickness and annealing temperature, reaching a minimum of 2.96 × 10−5 Ω cm for the 40 nm film annealed at 300 °C. Similarly, the sheet resistance declined to 6.45 Ω/sq for the 50 nm film at the same temperature. Magnetic characterization indicated enhanced domain continuity and increased low-frequency magnetic susceptibility (χac) with both greater thickness and higher annealing temperature. The highest χac value of 1.15 was recorded for the 50 nm film annealed at 300 °C at a resonance frequency (fres) of 50 Hz. These improvements are attributed to thermally induced grain growth, reduced surface roughness, lower defect density, and improved domain alignment. Overall, the findings demonstrate that optimizing the film thickness and annealing conditions significantly enhances the multifunctional properties of Ni80Ce20 thin films, making them promising candidates for magnetic, electronic, and spintronic applications.