Studying structural, magnetic and morphological features of electrochemically fabricated thin films of Co–Ni–Fe with different Fe compositions

Highlights: • Co–Ni₆₇, Co–Ni₆₁–Fe₆ and Co–Ni₅₄–Fe₁₃ thin films were fabricated. • Increasing Fe content led to a strong improvement in the soft magnetic features. • Very fine grains with an average size of about 50 nm were achieved. • The width of magnetic stripe domains varied in accordance with the Fe composition. • Morphological and structural parameters were affected by the Fe composition. In this work, a detailed study on the influence of the Fe composition on the crystallite size, lattice parameter, crystallographic texture, coercive field (H_c), magnetic squareness ratio (SQR), domain structure, surface roughness and grain size in electroplated Co–Ni–Fe deposits was carried out. For this aim, Co–Ni₆₇, Co–Ni₆₁–Fe₆ and Co–Ni₅₄–Fe₁₃ thin films with different Fe compositions were fabricated using electrochemical deposition technique. The results showed that the composition of Fe in the deposit depends on the concentration of Fe ions in the electroplating solution. An increase in the Fe composition caused a noticeable reduction in the size of crystallites and induced a considerable enhancement in the strength of the preferred orientation being in the [111] direction. It was also observed that an increase in the Fe composition makes the lattice parameter larger. Compared to other deposits, the Co–Ni₅₄–Fe₁₃ with the highest Fe composition exhibited a lower surface roughness and a more compact nodular surface topography consisting of relatively finer grains. All deposits displayed a stripe domain (SD) structure, an in–plane magnetic hysteresis loop with a vertical magnetization component and a semi–hard magnetic property. However, the H_c value, SQR parameter and SD width varied in accordance with the Fe composition.