Synthesis and Properties of the Layered Oxycarbonates Sr2-xBaxCuO2(CO3)

Pulsed Laser Deposition of Ba2-xAxCuO2CO3 (A = Ca, Sr) Thin Films, m = 0 Member of the Series (CaCuO2)m(Ba2-xAxCuO2CO3)n (A = Ca, Sr)

“…XRD showed that the periodicity along the c axis, normal to the substrate, is 7.8 Å. Such a value is consistent with that expected for the m = 0 member and suggests that the film is c axis oriented. The ED study indicates textured but not epitaxial films.…”

“…These parameters correspond to those of the m = 0 member, Ba 2- x Ca x CuO 2 CO 3 . The c parameter refined from XRD data, is significantly smaller than that of the calcium-free oxycarbonate, Ba 2 CuO 2 CO 3 , 7.8 Å instead of 7.97 Å, attesting that calcium partly replaces barium. The EDS analyses performed in several zones of the film show that the actual cationic composition of the film corresponds to Ba 2 CaCu 2 , i.e., in agreement with the nominal one Ba 2 CaCu 2 O 4 CO 3 .…”

Sub-solidus relations in CaOBaOCuO with and without carboxyl contamination

“…4) of these materials showed strong absorptions due to the internal vibration modes, vl ~ v4, of CO 3, which are, as expected, absent in the spectra of the 143 and 173 oxides. The relative intensities and line profiles (asymmetry) of these absorptions are typical of those of oxycarbonates [24] but distinct from those of BaCO 3 (curve 4). Notably, the v3 mode of CO 3 in a oxycarbonate shifts toward lower frequency and also becomes either split or asymmetric as compared with that in BaCO 3.…”

Nanostructural Transitions Related to Flexible Shearing Phenomena in the Superconductors Hg1−xVxSr4−yBayCu2O7−δCO3

“…-For samples with y Ͼ 2.65, isolated (100) collapsedtype grains have been characterized by ED but the majority phases are the 1201 cuprate, Hg 1Ϫx V x Sr 2Ϫy Ba y CuO 5Ϫͳ (14), and the copper oxycarbonate, Sr 2Ϫy Ba y CuO 2 CO 3 (15).…”