Synthesis of Cobalt Oxide Nanowhiskers by Thermal Decomposition of Inorganic Precursor and Study of the Magnetic Properties

In recent years, there has been an increasing interest in developing materials with low-dimensional nanostructure such as nanotubes and nanowhiskers due to their potential technological application in nanoscale devices [1].Cobalt oxides belong to the family of transition-metal oxides and the most stable phase, Co3O4, is an intrinsic p-type semiconductor (direct optical bandgaps at 1.48 and 2.19 eV) [2]. Co3O4 exhibits a normal spinel crystal structure with occupation of tetrahedral sites by Co2+ and octahedral sites by Co3+. Its magnetic moment arises due to Co2+ ions largely because of spins, with a small contribution from spin–orbit coupling. So far, there has been few literature reporting cobalt or cobalt oxide nanowhiskers. Xu et al. [3] synthesized Co nanowires composed of nanowhiskers in the pore-wall modified-alumina by adjusting the electrodeposition parameters. Recently Wang et al. synthesized one-dimensional arrays of Co3O4 nanoparticles by the thermal treatment of cobalt oxalate precursor at 420 °C [4]. Among various techniques developed for the synthesis of magnetic nanoparticles, thermal decomposition is one of the most common to produce stable monodisperse suspensions with the ability of self-assembly. Recently, our groups prepared Co and Co3O4 via thermal decomposition a new precursor, [Bis(salicylidene)cobalt(II)], [5]. The aim of the present work is to prepare Co3O4 nanowhiskers using thermal decomposition of inorganic precursor