Low pressure metalorganic chemical vapour deposition （LP-MOCVD） growth and characteristics of InAsSb on （100） GaSb substrates are investigated. Mirror-like surfaces with a minimum lattice mismatch are obtained. The samples are studied by photoluminescence spectra, and the output is 3.17μm in wavelength. The surface of InAsSb epilayer shows that its morphological feature is dependent on buffer layer. With an InAs buffer layer used, the best surface is obtained. The InAsSb film shows to be of n-type conduction with an electron concentration of 8.52 × 10^16 cm^-3.
By orthogonal design theory, technological parameters of chrysanthemum-like ZnO particles prepared in a hydrothermal process are optimized. This paper reports a set of technological parameters for growing chrysanthemumlike ZnO particles on a large scale. It investigates the morphologies and crystalline structures of the as-synthesized three-dimensional ZnO particles with a scanning electron microscope, x-ray diffractometer and transmission electron microscope, and the possible growth mechanism on the three-dimensional ZnO particles. The experimental results indicate that the values of ε′ε″ and tan δe gradually increase in the X band with the improvement of the developmental level of chrysanthemum-like ZnO particles, implying that the electromagnetic wave absorbing property depends on the morphologies of three-dimensional ZnO particles.
Through hydrothermal process, the chrysanthemum-like ZnO particles are prepared with zinc acetate dihydrate （Zn（CH3COO）2·2H2O） and sodium hydroxide （NaOH） used as main resources under the different concentrations of surfactant polyacrylamide （PAM）. The microstructure, morphology and the electromagnetic properties of the as-prepared products are characterized by high-resolution transmission electron microscopy （HRTEM）, field emission environment scanning electron microscope （FEESEM） and microwave vector network analyzer, respectively. The experimental results indicate that the as-prepared products are ZnO single crystalline with hexagona wurtzite structure, that the values of slenderness ratio Ld are different in different PAM concentrations, and that the good magnetic loss property is found in the ZnO products, and the average magnetic loss tangent tan δu increases with PAM concentration increasing, while the dielectric loss tangent tan ~e decreases.
