Tadashi Sugihara

Improved cycle performance of orthorhombic LiMn0.95−xMxCr0.05O2; M = Al, Ga, Yb and In, synthesized by hydrothermal technique

Abstract The effect of chemical substitution on improving cycle performance of orthorhombic LiMnO 2 ( o -LiMnO 2 ) was studied at the nominal compositions of LiMn 0.95− x M x Cr 0.05 O 2 ; M=Al, Ga, Yb and In, 0.01 x 0.92 In 0.03 Cr 0.05 O 2 was confirmed as the optimum composition. The crystal structure refinement showed that chemical substitution varied the average ionic radii of cation sites in o- LiMnO 2 . The ratio of average ionic radius at Mn site to that of Li site of the optimum compound was 0.87. This value was larger than that of no-substituted LiMnO 2 ; 0.84. TEM observation revealed that stacking faults were observed in the LiMn 0.92 In 0.03 Cr 0.05 O 2 grains. It is assumed that these two factors, controlling ionic radii and introducing stacking faults, are key parameters for improving cycle performance. However X-ray diffraction data and discharge curves suggested that phase transformation from orthorhombic to cubic spinel occurred during charge–discharge cycle.

Selection of kinetic energy of laser ablated particles

Controlling the kinetic energy of deposition species is an effective way to improve thin films physical properties. An apparatus that can select the kinetic energy of laser ablated particles was developed. It was demonstrated that the energy of laser ablated particle was selected by chopping with the slit of rotating disk. This apparatus was applied to thin film deposition and it was useful to improve surface morphology because the number of droplets on the film drastically decreased.

Selection of kinetic energy of laser-ablated particles and its application for deposition of Au, Pt and Ag thin films

Abstract Controlling the kinetic energy of deposition species is an effective way to improve a thin films physical properties. An apparatus that can select the kinetic energy of laser-ablated particles was developed. It was demonstrated that the energy of the laser-ablated particles was selected by chopping with the slit of a rotating disk. The energy profile of each ablated particle is illustrated, and the relationships between the selected velocity region and the selection conditions, such as disk rotation speed and delay time, are demonstrated. This apparatus was applied to the deposition of Au, Pt and Ag thin films. This process was also useful to improve surface morphology because the number of droplets on these films drastically decreased.