Phase evolution of YBa2Cu3O7-delta (YBCO) thin films prepared by a newly-developed fluorine-free sot-gel method were studied by combined use of in situ high temperature optical microscope observation and X-ray diffraction. The reaction sequences associated with yttrium, barium and copper in this route were determined respectively. It was found that the reactions that take place were strongly dependent on the experimental conditions such as water partial pressure. The formation of YBCO started around 710 degrees C and continued up to 800 degrees C for about 15 min. The formation mechanism of YBCO was found to be dependent on the barium containing phases, which were controlled by the experimental conditions. The formation of a- and c-axes oriented YBCO grains was also found to be governed by the processing reactions. (c) 2006 Elsevier B.V. All rights reserved.
Formation of Polynuclear Cadmium Pivalates in Exchange Reactions
作者:N. V. Gogoleva、A. A. Sidorov、Yu. V. Nelyubina、M. A. Shmelev、G. G. Aleksandrov、G. N. Kuznetsova、M. A. Kiskin、I. L. Eremenko
DOI:10.1134/s107032841808002x
日期:2018.8
Abstract The exchange reaction of CdCl2 ⋅ 2H2O with KPiv affords cadmium(II) trimethyl acetate complexes (K[Cd6(Piv)12Cl] ⋅ 2MeCN (I), [K2Cd3(Piv)8(H2O)6] (II), and [Cd(Piv)2(Н2О)2] (III) as a mixture with complex II and [K3Cd2(Piv)7(MeCN)2]n (IV) (HPiv is trimethylacetic acid). The exchange reaction of CdSO4 ⋅ 8/3H2O with Ba(Piv)2 makes it possible to obtain complex III in a quantitative yield. Complex