Papers by Author: Hong Xing Gu

Abstract: The Bi2MnxV1-xO5.5- powders were synthesized by high temperature melting method. The effect of Mn dopant concentration on the crystal structure and chemical composition was studied. The crystal structure was determined by X-ray powder diffraction. The chemical composition was tested by X-ray fluorescence (XRF) and Energy Disperse Spectroscopy (EDS). When x < 0.2 the Aurivillius structure solid solution coexisted with few BiVO4. When 0.2 ≤ x ≤ 0.3 the γ-phase Bi2MnxV1-xO5.5- solid solution with tetragonal structure formed and the maximum Mn atomic content was 2.14%. When x ≥ 0.4 the manganese oxide secondary phase appeared. And when x = 0.8 the Bi7VO13 structure solid solution formed while the Aurivillius structure disappeared.

Abstract: NiO-YSZ (NiO-yttria stabilized zirconia, 3:2, wt.%) and samaria doped ceria (SDC) tapes were prepared by aqueous tape casting. NiO-YSZ anode-supported SDC film electrolyte half-cell was fabricated by laminating and co-sintering at 1400°C for 2 h. The single cell was prepared after LSCF-SDC (lanthanum strontium cobalt ferrite-SDC, 1:1, wt.%) cathode was coated on the electrolyte surface and sintered at 1300 °C for 2 h. The discharge performance of the single cell was tested from 500 °C to 800 °C at different H2 flow rate. Results showed that the relationship between current (I) of and H2 flow rate (ν) was I = 8 × 106 ν. Before reaching the threshold value of H2 flow rate, the current density of single cell increased with the increasing of H2 flow rate. However, the current density did not change with increasing of H2 flow rate over the threshold value. The open circuit voltage (OCV) of single cell at 500°C, 600°C, 700°C, 800°C was 0.978, 0.921, 0.861, 0.803 V, respectively. The maximum power density reached 93.03 mW/cm2 at 800°C. The resistance of interface layer between Ni-YSZ anode and SDC electrolyte was the key impact on the power density.

Abstract: BiFeO3-based single-phase multiferroics have been widely studied in both ceramics and films. However, the macroscopic magnetic properties of BiFeO3 ceramics were now most very weak. In this work, MnO2 and Co2O3 were used as B-site substitutes in BiFeO3 ceramics in order to the enhancement of magnetic properties. The change of magnetization was analyzed based on the phase composition and the microstructure of ceramics.