Magnetic Properties of Ni/NiO Nanowires Deposited onto CNT/Pt Nanocomposites

February 4, 2008 2008
Verónica Salgueiriño-Maceira, Miguel A. Correa-Duarte, Manuel Bañobre-López, Marek Grzelczak, Michael Farle, Luis M. Liz-Marzán, and José Rivas
Adv. Funct. Mat., 2008, 18, 616–621

 

Several nanometer-scale technological applications rely on the promising scenario of highly anisotropic magnetic materials. Bearing this in mind, we have studied the structure, magnetic properties, and interfacial exchange anisotropy effects of unique wires of Ni/NiO synthesized using carbon nanotubes as substrates. Structural analyses of these nanocomposites in correlation with magnetic measurements show that the crystalline NiO outer shells cause an enhanced exchange bias, providing an extra source of anisotropy that leads to their magnetization stability. These Ni/NiO nanowires, with a spin-glass-like behavior and with their magnetic moments in a blocked state over a wide temperature range that includes room temperature, should therefore inspire further study concerning the applicability of anisotropic structures.