Zhou et al. Nanoscale Research Letters 2011, 6:276 http://www.nanoscalereslett.com/content/6/1/276 N A N O E X P R E S S Open Access Fabrication and magnetic properties of granular Co/porous InP nanocomposite materials Tao Zhou1, Dandan Cheng1, Maojun Zheng1*, Li Ma2 and Wenzhong Shen1 Abstract A novel Co/InP magnetic semiconductor nanocomposite was fabricated by electrodeposition magnetic Co nanoparticles into n-type porous InP templates in ethanol solution of cobalt chloride. The content or particle size of Co particles embedded in porous InP increased with increasing deposition time. Co particles had uniform distribution over pore sidewall surface of InP template, which was different from that of ceramic template and may open up new branch of fabrication of nanocomposites. The magnetism of such Co/InP nanocomposites can be gradually tuned from diamagnetism to ferromagnetism by increasing the deposition time of Co. Magnetic anisotropy of this Co/InP nanocomposite with magnetization easy axis along the axis of InP square channel was well realized by the competition between shape anisotropy and magnetocrystalline anisotropy. Such Co/InP nanocomposites with adjustable magnetism may have potential applications in future in the field of spin electronics. PACS: 61.46. +w · 72.80.Tm · 81.05.Rm · 75.75. +a · 82.45.Aa Introduction The fabrication and magnetic properties of magnetic nanomaterials or nanocomposites have been the center of attraction among researchers, due to their potential applications in high-density data storage devices, mag- neto-optical sensors, spintronic devices, and interesting fundamental physical phenomena [1-8]. Particularly, elec- trodeposition of magnetic nanoparticles, nanowires, and nanotubes in ordered nonmagnetic templates has attracted great attention because of its low cost, preferred yield of order magnetic nanomaterials, and size-adjusta- ble properties [2,4,5,9-20]. The most popular template is anodic alumina oxide (AAO) membrane because of its uniform channel arrays and chemical inertness, which has been widely used for producing magnetic nanostruc- tures, including cobalt ferrite nanodot arrays [13], Fe, Co, and Ni nanowires, nanotubes, and nanoparticles arrays [5,8,14-19], FeNi ferromagnetic alloy, CoPt nanotubes [9], and so on. The growth and magnetic properties of magnetic nanomaterials in AlN, MgO, polymer tem- plates, and superlattice matrices were also reported * Correspondence: mjzheng@sjtu.edu.cn 1Laboratory of Condensed Matter Spectroscopy and Opto-Electronic Physics, and Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics, Shanghai Jiao Tong University, Shanghai, 200240, People’s Republic of China Full list of author information is available at the end of the article [21-25]. Up to now, both theoretical and experimental works have focused mainly on insulation templates, while there has not been much study conducted on the growth of magnetic nanomaterials in semiconductor templates. Recently, electrodeposition of Fe, Co, Ni, and FeNi alloy into porous silicon semiconductor matrix has been studied [11,26-29]. It was found that the novel magneti- zation behaviors of these nanocomposite materials depended on deposits and matrices. For example, Granit- zer et al. [29] found a new twofold switching of magnetic hysteresis curve in Ni/porous silicon composites. There- fore, electrochemical deposition of ferromagnetic metals into semiconductor templates and investigation of their magnetic properties may provide a new avenue for nano- fabrication and have important applications ranging from magnetic sensing to the field of spin electronics [5,6,29]. In addition, owing to its direct band gap and enhanced nonlinear optical response, increasing interest has been focused on porous InP because of its potential applica- tions in nanoscaled Schottky diodes, waveguides, solar cells, and for fabricating nanocomposite materials [30-34]. However, to our knowledge, there are no reports on the composite between porous InP matrix and mag- netic materials. Furthermore, as a typical ferromagnetic materials, Co nanostructures, especially for granular Co, embedded in nonmagnetic matrices have been widely studied, where the matrices most focused were of three © 2011 Zhou et al; licensee Springer. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.