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先以BaCO3和Bi2O3为原料由传统的固相反应制备纯BaBiO3,然后在低温下将用KOH-KF熔盐处理这样的拓扑反应合成了Ba1-xKxBiO3超导体.所有样品均进行了粉末X射线衍射(XRD)和磁性表征.XRD结果表明,所得Ba1-xKxBiO3样品均为纯相,且均可用赝立方晶胞指标化.磁性测量表明所有样品具有超导电性,最高超导转变温度(Tc)为30.6 K.讨论了反应时间、前驱体与熔盐质量比对超导转变温度的影响.最佳的反应条件为:反应温度450°C,反应时间4 h,BaBiO3:KOH:KF质量比1:5:2.5.
Pure BaBiO3 was prepared by conventional solid-state reaction using BaCO3 and Bi2O3 as raw materials, and Ba1-xKxBiO3 superconductors were synthesized by such topological reaction with KOH-KF molten salt at low temperature.All the samples were characterized by powder X-ray diffraction XRD and magnetic characterization.The XRD results showed that the samples of Ba1-xKxBiO3 were pure phase and all of them could be calibrated with pseudocubic cells.The magnetic measurements showed that all the samples had superconductivity and the highest superconducting transition temperature (Tc) was 30.6 K. The effects of reaction time, mass ratio of precursor to molten salt on the superconducting transition temperature were discussed.The optimum reaction conditions were as follows: the reaction temperature was 450 ° C, the reaction time was 4 h, the mass ratio of BaBiO3: KOH: KF was 1: 5 : 2.5.