SYNTHESIS AND INVESTIGATION OF FeNi AND FeCo BINARY NANOALLOY

Abstract

FexNi100-x and FexCo100-x (x = 20, 40 and 80) alloy nanoparticles (NPs) were synthesized by sonofragmentation process, a facile one-step technique to produce NPs directly from bulk powders. The structural properties were studied by using X-ray Diffraction (XRD). The XRD shows the crystalline structure of the alloy samples and the size of the crystallites were calculated 35 nm and 19.3 nm for Fe-Ni and Fe-Co respectively with significant amount of phase purity. The compositions of Ni, Fe and Co in the alloy are confirmed from energy dispersive spectroscopy (EDS). It also reveals that there is no unwanted element in the alloys. Scanning electron microscopy (SEM) reveals the aggregation or cluster of spherical NPs with wide size distribution from 20 to 50 nm for all compositions of nanoalloys. The vibrating sample magnetometer (VSM) illustrates the superparamagnetic behavior of the alloys. The saturation magnetization (Ms) is found to be 57, 66 and 105 emu/g for Fe20Ni80, Fe40Ni60 and Fe80Ni20 NPs alloys respectively. The values of Ms were found to be 107, 131, and 153 emu/g for Fe20Co80, Fe40Co60 and Fe80Co20 NPs alloys respectively. However, the coercivity (Hc) is observed 73, 64 and 57 Oe for Fe20Ni80, Fe40Ni60 and Fe80Ni20 respectively. The value of Hc is also observed 128, 113 and 72 Oe for Fe20Co80, Fe40Co60 and Fe80Co20 respectively. It can be noticed that with increasing Fe content magnetization increases whereas corercivity decreases. The increasing magnetization may be ascribed to the incorporation of higher magnetic moments into the compositions. Such compositional dependent nature shows an important approach to attain tunable magnetic properties of Fe-Ni and Fe-Co NPs for their many practical applications. Moreover, the synthesized high magnetization Fe-Ni and Fe-Co nanoalloy can be used for XV various potential applications, and also this simple and environment friendly technique can be extended to synthesize other nanostructures.