Designed synthesis of FeₓCo₁₀₀₋ₓ alloy nanoparticles by polyol reduction: an evolution of structural, morphological and magnetic properties

FexCo100-x nanoparticles with different stoichiometry (x = 0-100) have been prepared by a facile synthesis process and compositions confirmed using X-ray fluorescence spectroscopy. X-ray diffraction measurements suggest alloy formation in the body-centered cubic (BCC) phase, with a progressive shift of peak positions to account for the stoichiometric changes. The evolution of nanoparticle morphology is from cubic for iron to hexagonal for cobalt, and the entire composition range has been examined. Magnetic behavior has been accessed by Mössbauer spectroscopy and vibrating sample magnetometric measurements, which suggests an increase of magnetization values of iron upon alloying with cobalt. A detailed account of the synthesis scheme has been presented, to achieve uniform alloy nanoparticles in the pristine state with minimum aggregation and surface oxidation, by carefully adjusting the reaction timescales.This work was supported in part by the University of Delhi through the Institutions of Eminence (IoE) Scheme and in part by the Science and Engineering Research Board (SERB) of the Department of Science and Technology, Government of India, through the SERB Project under Grant EMR/2016/002437. The work of Moditma was supported by the Council for Scientific and Industrial Research (CSIR) in the form of fellowship