Magnetic Anisotropy and Microstructure in Electrodeposited Quaternary Sn-Fe-Ni-Co Alloys with Amorphous Character

Sn-Fe-Ni-Co quaternary alloys, in the composition range of 37-44 at% Sn, 35-39 at% Fe, 6-8 at% Ni and 13-17 at% Co, were prepared by direct current (DC) and pulse plating (PP) electrodeposition. The alloy deposits were characterized by XRD, Fe-57 and Sn-119 conversion electron Mossbauer spectroscopy, SEM-EDX and magnetization measurements. XRD revealed the amorphous character of the quaternary alloy deposits. The dominant ferromagnetic character of the deposits was shown by magnetization and Mossbauer spectroscopy measurements. Room temperature Mossbauer spectra showed minor paramagnetic phases, where their occurrences (similar to 3-20%) are correlated to the electrodeposition parameters (J(dep) from -16 to -23 mA/cm(2) for DC, J(pulse) from -40 to -75 mA/cm(2) for PP), the composition and the saturation magnetization (similar to 52-73 emu/g). A considerable difference was found in the magnetization curves applying parallel or perpendicular orientation of the applied fields, indicating magnetic anisotropy both in DC and pulse plated alloy coatings.