Structural, magnetic and electron transfer effect of Cr additive on Fe<inf>65</inf>Co<inf>35</inf> nanopowder fabricated mechanical alloying

Abstract

In this paper, structural, electrical and magnetic properties of nanocrystalline (Fe<inf>70</inf>Co<inf>30</inf>)<inf>100-x</inf>Cr<inf>x</inf> (x=0, 5) powders produced by mechanical alloying (MA) have been investigated. Some parameter such as milling times (up to 100h) and compositional ration (0% and 5% Cr) was investigated in this study. Characterizations of the prepared powders were carried out by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD), elemental map analysis, energy-dispersive X-ray spectroscopy (EDS) and vibratory sample magnetometer (VSM) methods. The results show the formation of the Fe(Co) and Fe(Co, Cr) solid solutions completed in 32 and 100h of milling time, respectively. X-ray diffraction experiment results indicate that Fe<inf>65</inf>Co<inf>35</inf> and (Fe<inf>65</inf>Co<inf>35</inf>)<inf>95</inf>Cr<inf>5</inf> average grain size reduces from 180nm before milling process (0h) to about 18 and 10nm with increasing of milling time, respectively. Magnetic properties of prepared nanoalloys were investigated using vibratory sample magnetometer method and the results show interesting changes in milling process. The effect of chromium additive also was performed using electrochemical impedance spectroscopy method. This study shows the presence of chromium increasing charge transfer resistant in electrochemical process. © 2015 Elsevier B.V.