Magnetic behavior of nanocrystalline Cu–Ni–Co alloys prepared by mechanical alloying and isothermal annealing

• Published in: Journal of alloys and compounds 2008-06, Vol.457 (1), p.10-14
• Main Authors: Mondal, B.N., Basumallick, A., Chattopadhyay, P.P.
• Format: Article
• Language: English
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cu–Ni–Co; Exact sciences and technology; Isothermal annealing; Magnetic properties; Magnetic properties and materials; Magnetic properties of nanostructures; Mechanical alloying; Nanocrystalline; Physics
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2007.02.139

The structural and magnetic properties of nanocrystalline Cu–Ni and Cu–Ni–Co alloys prepared by mechanical alloying and subsequent isothermal annealing in the temperature range of 350–650 °C has been investigated systematically. The average grain sizes of Cu–Ni and Cu–Ni–Co alloy systems were found to be in the range of 5–8 nm after 30 h of milling and 21–40 nm after isothermal annealing of as-milled samples. Here, it is shown that the magnetic properties ( H c, M r and M s) of the nanocrystalline alloys undergo changes by the variation in microstructural constituents, grain size and evolution of phases. The alloy containing 10 wt% Co shows notable improvement in the magnetic properties. Phases present in the ball milled samples and the isothermally annealed ball milled product were identified and characterized by X-ray diffraction (XRD) and differential scanning calorimetric (DSC) techniques and the results were correlated with the magnetic properties of the alloys.