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


  • V.S.-M. and M.A.C.-D. acknowledge the Isidro Parga Pondal Program fellowships (Xunta de Galicia, Spain). V.S.-M. particularly thanks F. Rivadulla (Universidade de Santiago de Compostela) for helpful discussions. This work has been supported by the Ministerio de Educación y Ciencia under grant No. NAN2004-09195-C04-01, Consolider-Ingenio Nanobiomed, by the Spanish Xunta de Galicia under grant No. PGIDIT06PXIB314379PR, and the EU Research Training Network “Syntorbmag”.


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.