BaTiO3-coated Fe nanofibers are synthesized via a three-step process. α-Fe2O3 nanofibers with an average diameter of approximately 200 nm are first prepared using an electrospinning process followed by a calcination step. The BaTiO3 coating layer on the nanofiber is formed by a sol-gel process, and a thermal reduction process is then applied to the core-shell nanofiber to selectively reduce the α-Fe2O3 to Fe. The thickness of the BaTiO3 shell is controlled by varying the reaction time. To evaluate the electromagnetic (EM) wave-absorbing abilities of the BaTiO3@Fe nanofiber, epoxy-based composites containing the nanofibers are fabricated. The composites show excellent EM wave absorption properties where the power loss increases to the high frequency region without any degradation. Our results demonstrate that the BaTiO3@Fe nanofibers obtained in this work are attractive candidates for electromagnetic wave absorption applications.

Diameter-controlled tin oxide nanofibers have been successfully prepared using electrospinning and a subsequent calcination process; their diameters, morphologies, and crystal structures have been characterized. The diameters of the as-spun nanofibers can be decreased by lowering the concentration of a polymer and a tin precursor in the electrospinning solution because of the decrease in the solution viscosity. The crystal structure of the nanofibers calcined at various temperatures from 200˚C to 800˚C has been proved to be the tetragonal rutile of tin oxide; crystallinity is improved by increasing the temperature. However, nanofibers with lower concentrations of tin precursor do not maintain their fibrous structures after calcination at high temperatures. In this study, the effect of the relationship between the precursor concentration and the calcination temperature on the diameter and the morphology of the tin oxide nanofiber has been systematically investigated and discussed.

Fundamental experiences have been studied for development of pre-treatment process of Sn by-prod-ucts such as solders. Dry and wet separation/recovery processes were considered by the differences of physicalproperties. The by-products, which are analyzed by solder metal and oxides. The metal and oxide were simplyseparated by dry ball-milling process for 12 hours, after that recovery metal powder might be reusable as lead orlead-free solders. In terms of wet separation process, samples were dissolved in HNO3+H2O2 and the precipita-tion were analyzed by SnO2. Overall efficiency of recovery might be increasing via developing simple pre-treat-ment process.

A new High Frequency Induction Heating (HFIH) process has been developed to fabricate dense reinforced with Fe-Ni magnetic metal dispersion particles. The process is based on the reduction of metal oxide particles immediately prior to sintering. The synthesized /Fe-Ni nanocomposite powders were formed directly from the selective reduction of metal oxide powders, such as NiO and . Dense /Fe-Ni nanocomposite was fabricated using the HFIH method with an extremely high heating rate of . Phase identification and microstructure of nanocomposite powders and sintered specimens were determined by X-ray diffraction and SEM and TEM, respectively. Vickers hardness experiment were performed to investigate the mechanical properties of the /Fe-Ni nanocomposite.