Structural analysis and magnetic characterization of ternary alloys (Co–Fe–Ni) synthesized by mechanical alloying

Abstract

In this research, the synthesis of Co–Fe–Ni ternary alloys in different compositions (Co40Fe30Ni30, Co30Fe40Ni30 and Co30Fe30Ni40), and their structural and magnetic properties were assessed. These alloys were milled during 7 h by mechanical alloying (MA), after of the milling time, the results of the structural analysis, shown three solids solutions obtained with fcc-structure (Co(FeNi)–fcc, Fe(CoNi)–fcc and Ni(FeCo)–fcc). As a consequence of the process of synthesis, the crystal size refinement was observed in all cases, meanwhile, the particle size increased due to the powders ductility.The magnetic properties at room temperature were studied to observe the saturation magnetization (Ms), before and after of the milling, the results of the un-milled powders were 140, 130 and 110 A m2/kg for Co40Fe30Ni30, Co30Fe40Ni30 and Co30Fe30Ni40 respectively, after of mechanical alloying, the MS increased to 162, 166 and 150 A m2/kg. On the other hand, the coercive field (HC) values decreased drastically from 6.13 kA/m (~77 Oe), 4.77 kA/m (~60 Oe) and 5.57 kA/m (~70 Oe) before of the milling process, to 0.365 kA/m (~4.6 Oe), 0.296 kA/m (~3.7 Oe) and 0.306 kA/m (~3.8 Oe) after the milling for Co40Fe30Ni30, Co30Fe40Ni30 and Co30Fe30Ni40, respectively.

Keywords

• Mechanical alloying
• Ternary alloys
• Magnetic properties
• Fcc-structure
• Soft magnetics