Magnetic properties of TiO2/Ni hybrid nanotube arrays by electrophoretic deposition

Magnetic Ni nanotubes (NTs) were fabricated in the pores of the self-aligned TiO2 NT arrays by direct current electro-deposition. Crystal structure and morphologies of the TiO2/Ni hybrid NT arrays were characterized by XRD, TEM, and SEM. The results indicated that the Ni NTs have no preferred orientation and were polycrystalline structure. Room-temperature magnetic property of the NTs was studied. The magnetic easy axis was parallel to the nanotube's channel axis attributing to the large shape anisotropy. Temperature dependent magnetization showed that the thermal energy decreasing caused an increase in coercivity by the enhanced magnetocrystalline anisotropy and dipolar interactions between NTs at lower temperatures. (C) 2012 Elsevier B. V. All rights reserved.