Easy Controlled Properties of Quaternary FeNiCrCd Thin Films Deposited from a Single dc Magnetron Sputtering Under the Influence of Deposition Rate

Abstract

The quaternary FeNiCrCd thin films were produced from a single FeNiCrCr source on a commercial flexible polymer substrate using one dc magnetron sputtering technique. For that, a series of the films with a thickness of 50 nm were produced at different deposition rates of 0.02, 0.04, 0.06, and 0.08 nm/s, separately. In this study, as far as concerned, this was the first time that structural and magnetic properties of FeNiCrCd thin films were investigated. According to compositional analysis, the Fe and Cr contents slightly decreased with increasing deposition rate while Ni was almost constant, whereas those of the amount of Cd atoms increased. However, the atomic amounts of Fe and Cd in the films are quite different from those of the source material. The change of the atomic contents in the films from the source may be attributed to the relatively different bond energy/melting point of metals which have different contents sputtered from source material since this physical parameter is very significant for the sputtering process. For crystal structural analysis, a combination of hexagonal close-packed (hcp) and body-centered cubic (bcc) were observed. The peak intensity of the bcc-dominated planes decreased while the hcp-dominant plane increased since the change in peak intensities is compatible with the compositional analysis with increasing deposition rate. And, the grain sizes decreased gradually from 40.1 to 23.4 nm, with increasing deposition rate from 0.02, to 0.08 nm/s. Also, the film surfaces transformed from a rough to smooth surfaces with decreasing grain sizes as deposition rate increased. For magnetic analysis, the saturation magnetization Ms values decreased as 1030, 773, 730, and 217 emu/cm3 with increasing deposition rate as 0.02, 0.04, 0.06, and 0.08 nm/s, respectively. In the same manner, the coercivity Hc values were found as 11, 7, 6, and 2 Oe with the deposition rate of 0.02, 0.04, 0.06, and 0.08 nm/s, respectively. The decrease of the Hc may have primarily come from the transformation of rough to smooth surface of the films. It may also be said that the films showed soft magnetic properties due to their low Hc values with increasing deposition rate. Thus, the magnetic properties of the quaternary FeNiCrCd alloy films were seen to be easily improved with the deposition rate parameter for potential use in different industrial applications.