*3.1. Substrates Elemental Analysis*

The average elemental content of the manufactured SS 316L and Cu substrates, which were each examined three times by the XRF, are given in Table 1. In addition, the XRD pattern corresponds well with the XRF analysis as suggested by the sharp diffraction Bragg's peaks shown in Figure 2a,b, where the SS substrate (Figure 2a) showed peaks at 2*θ* = 43.6◦, 50.9◦, and 74.7◦ corresponding to the planes (111), (200), and (220) austenite gamma phase; and the Cu substrate (Figure 2b) illustrated diffraction peaks at 2*θ* = 43.2◦, 50.4◦, and 74.1◦ corresponding to the planes (111), (200), and (220) of pattern (PDF Card No.: 03-065-9026). Hence, this confirms that the bulk formation of the as-prepared substrates used for the deposition experiments are of Cu and SS 316L in its austenite phase.


**Table 1.** Averaged XRF elemental analysis of SS 316L and Cu substrates.

**Figure 2.** X-ray diffraction pattern of: (**a**) SS 316L substrate, and (**b**) Cu substrate.
