Papers by Keyword: Oxygen Pressure

Abstract: YBa₂Cu₄O₈ has emerged as better choice in superconducting application thank to it strong thermal stability. High pressure techniques had been employed for the preparation of YBa₂Cu₄O₈ but it might costly and/or inconvenient. Several research groups had showed that the YBa₂Cu₄O₈ can also be prepared by conventional solid state method with heating at 1 atm oxygen pressure; however the phase formation processes are yet brief and clear. This work infiltrated the phase formation processes in preparing the YBa₂Cu₄O₈ under solid state method with heating at 1 atm oxygen pressure. The effectiveness of the use of sodium nitrate as an enhancer was brought to light by the experiment results. Significant YBa₂Cu₄O₈ phases were successfully synthesized.

Abstract: To investigate the effect of oxygen pressure on the synthesis of LiNiO2 cathode material for Li secondary battery, powder was prepared by emulsion method and calcined at 750°C for 24 h under various oxygen gas pressures. LiNiO2 single phase could be synthesized under oxygen pressure of 101.3~103.3 kPa but not under air atmosphere. Cation mixing in Li site of LiNiO2 lowered as oxygen pressure increased and was saturated around 103.3 kPa. The lowest cation mixing, 7.0% of Ni3+ in the Li site was obtained at 750°C for 24 h under 103.3 kPa of oxygen pressure.