Fabrication and temperature-dependent magnetic properties of one-dimensional embedded nickel segment in gold nanowires

In this paper, we elucidate the fabrication and temperature-dependent magnetic characteristics of Ni nanowires sandwiched in Au nanosegments. The nanowires were fabricated by electrochemical deposition in alumina templates with diameter of 100 nm and Ni segment length of around 800 nm. Structural analyses confirmed the formation of pure phase, crystalline multi-segmented Au-Ni-Au nanowires. Magnetic studies performed using a super-conducting quantum interface device-vibrating sample magnetometer reveal that ferromagnetism is induced in the wires due to the presence of Ni, which is ferromagnetic in nature. Temperature-dependent analysis shows that coercivity of the samples increases with decreasing temperature following Kneller's law for ferromagnetic nanostructures. The saturation magnetization shows an increasing trend as the temperature decreases according to the modified Bloch's law and this behavior is similar to that of ferromagnetic nanoparticles. (C) 2012 Elsevier B. V. All rights reserved.