Tuning structural properties, morphology and magnetic characteristics of nanostructured Ni‐Co‐Fe/ITO ternary alloys by galvanostatic pretreatment process

Abstract

In this research, the structural properties, surface morphology, and magnetic characteristics of nanostructured ternary ferromagnetic alloys grown by a cost‐effective and effortless two‐step electrochemical deposition method on indium tin oxide (ITO) substrates with and without a galvanostatic pretreatment process (GPP) were examined. The GPP was applied at various pretreatment current densities (PCDs) such as −10, −20, and − 30 mA/cm2. The effect of the PCD on the Ni, Co, and Fe contents is found to be insignificant and all resultant Ni‐Co‐Fe thin films show an abnormal co‐deposition. The films have nano‐sized crystallites ranging from 17.3 to 19.6 nm and showed a face‐centered cubic structure with the [111] preferential growth. Compared to the non‐GPP applied Ni‐Co‐Fe film, growing the ternary Ni‐Co‐Fe film on ITO at the PCD of −30 mA/cm2 causes an improvement in the crystal quality and a reduction in the particle size from 150 ± 50 to 70 ± 20 nm. A decrement in the surface roughness and coercivity was also achieved by applying the GPP at the PCD of −30 mA/cm2, but the opposite is true for the GPP performed at the PCD of −10 mA/cm2. The GPP has an effect on the magnetic Squareness Ratio (SQR), but the influence of the PCD on the SQR parameter is negligible. The obtained findings reveal that the properties of the Ni‐Co‐Fe/ITO ternary alloys can be tuned through the GPP applied in various PCDs. Highlights • The effect of the PCD on the Ni, Co, and Fe contents is found to be insignificant. • The films have nano‐sized crystallites and showed a face‐centered cubic structure with the [111] preferential growth. • The analysis reveals that the GPP changes the crystal quality, Hc parameter, surface roughness, and particle size of the films. • The GPP has an effect on the magnetic squareness ratio (SQR), but the influence of the PCD on the SQR parameter is negligible. • The films had nano‐sized crystallites ranging from 17.3 to 19.6 nm. • The films were ferromagnetic, and the Hc and SQR parameters of the films ranged from 30.2 to 42.7 Oe and from 8.8% to 19.6%.

Electrolyte pH dependence of composition, roughness parameters, particle diameter and magnetic features of nanostructured Fe‐Co‐Ni/ITO deposits prepared by electrochemical deposition method

“…This type of IP M-H loop has also been reported in recent studies for binary and ternary magnetic materials produced by the ECD and mechanical synthesis methods. 16,17,21,22,57,58 Table 2 also demonstrates that lowering the electrolyte pH causes an increase in the coercive field. The coercive field increases slightly from 29.4 Oe to 33.2 Oe as the pH of the electrolyte decreases from 4.7 to 3.9, and then increases sharply from 33.2 Oe to 41.3 Oe when the pH of the electrolyte drops from 3.9 to 3.2.…”

“…Other components are due the ITO glass and activated carbon. 21,28,33 The composition of the resultant deposits is illustrated in Figure 2. It is found that the deposits manufactured at high pH values of 4.7 and 3.9 contain very close Fe (12.4-12.8 at.%), Co (28.7-29.7 at.%) and Ni (57.9-58.5 at.%) contents.…”

“…As evident from Figure 4A ferred orientation. 16,21,23,28,[35][36][37][38][39] Moreover, the intensity of the (111) and (200) reflections first increases and then decreases with decreasing electrolyte pH, suggesting that the electrolyte pH plays a role on the degree of crystallisation of the films. The width and position of the (111) The surface morphologies were observed using an AFM and a SEM.…”

“…Electrochemical deposition (ECD) method, which is one of the most effective and most preferred synthesis methods, is widely used for this purpose due to its many well-known superior features. 16,17,21 Recently, we have investigated the effects of pretreatment current density, 21 deposit composition 16,22 and synthesis potential 23 on the ferromagnetic ternary thin film samples grown by ECD method. These experimental studies have indicated that the plating conditions and deposit composition considerably affect the characteristic features of the ferromagnetic ternary thin films.…”

Synergistic Influence of the Deposition Method, Postdeposition Annealing, and Textured Substrates on the Properties of ITO Thin Films

“…The statistical parameters, namely, RMS roughness ( S q ), skewness ( S sk ), kurtosis ( S ku ), and arithmetic mean height values ( S a ), were calculated using eqs –, respectively. The equations are obtained from ISO 25178 data. − …”