Cross-sectional SEM images of the nanostructured NiCr film fabricated using sputtering deposition with (a) increasing gas pressure of 4 Pa, 8 Pa, and 12 Pa, (b) decreasing gas pressure of 12 Pa, 8 Pa, and 4 Pa, (c) increasing sputter current of 0.2 A, 0.3 A, and 0.4 A, and (d) decreasing sputter current of 0.4 A, 0.3 A, and 0.2 A.