ZnO films are deposited on glass slides by radio frequency(RF) magnetron sputtering under different powers. The polycrystal structures and surface morphologies of the film are investigated. The optical transmission spectra for the ZnO films are measured within the range from 300 nm to 800 nm. The optical constants and thickness of the films are determined using a nonlinear programming method suggested by Birgin et al. The band gap of the film increases with reducing the nano-size of the film grains. The packing density of the films can be improved by reducing the RF power.
The gradient composite LiNi0.8Co0.2O2 was synthesized using spherical Ni(OH)2 particle coated by a sol-gel containing cobalt and lithium. The precursor was examined by DSC-TG. The gradient composite was characterized by SEM, EDS, XPS, XRD and ICP-AES. The XPS, EDS and ICP-AES results show that content of cobalt in the surface is higher than in the center of the spherical particle of the gradient composite. The first discharge specific capacity of the gradient composite sintered at 700 ℃ is 187.3 mAh·g-1.
