Ba-K-Bi-O超导体熔盐阳极电结晶研究

用ＸＰＳ和ＸＲＤ表征了Ｂａ－Ｋ－Ｂｉ－Ｏ超导体熔盐电结晶的阳极和阴 极产物，用ＳＥＭ分析了Ｂａ－Ｋ－Ｂｉ－Ｏ单生长形态。结果表明，阳极产物是Ｂａ－Ｋ－Ｂｉ－Ｏ超导体单晶，以台阶式方式生长。－Ｋ－Ｂ－

Investigation of the Anodic Electrocrystallization of Superconductor Ba-K-Bi-O from Molten Salts

The deposits on anode and cathode in electrocrystallization of Ba-K-Bi-Osuperconductor from molten salts were characterized by using XPS and XRD. The morphology of resulting Ba-K-Bi-O crystals was analyzed by using SEM. The results showthat the deposit on anode is superconducting Ba-K-Bi-O single crystals which grow assteps on the crystal faces. The deposit on cathode is controlled by the melt composition:the deposit is metallic Bi when the water content of KOH is relatively high; the depositis Bi2O3 when the water content is relatively low and the melt contains NO3-; the depositis metallic Zn when ZnO is added into the melt. The mechanism of electrocrystallizationof Ba-K-Bi-O superconductor is discussed. We suggest that Bi ions in the melt, may formcomplex ions with OH- ions, the latter migrate to the anode due to the action of convection, diffusion and electric migration. The formation of Ba-K-Bi-O and incorporationof Ba into the crystals may be related to highly oxidized species (e.g. O1-type oxygen)formed at the anode in the strong alkali melt.