As part of the study of interaction of the Ba2RCu3O6+z (R=lanthanides and Y) superconductor with SrTiO3 buffer, phase equilibria of the subsystem, R2O3-TiO2-CuO (R=Nd, Y, and Yb), have been investigated in air at 960 °C. While the phase relationships of the two phase diagrams with smaller R (Y and Yb) are similar, substantial differences were found in the Nd2O3-TiO2-CuO system, partly due to different phase formation in the binary R2O3-TiO2 and R2O3-CuO systems. R2CuTiO6 and R2Cu9Ti12O36 were the only ternary phases established in all the three diagrams. R2Cu9Ti12O36 belongs to the perovskite-related [AC3](B4)O12 family which is cubic Im3. Depending on the size of R3+, R2CuTiO6 crystallizes in two crystal systems: Pnma (R=La-Gd), and P63cm (R=Dy-Lu). The structure and crystal chemistry of the Pnma series of R2CuTiO6 (R=La, Nd, Sm, Eu, and Gd) are discussed in detail in this paper. Patterns for selected members of R2CuTiO6 have also been prepared and submitted for inclusion in the Powder Diffraction File (PDF). 相似文献
Japanese cedar wood powder (CWP) was chemically modified to a tertiary-amine-type adsorbent and studied for the selective recovery of Pd(II) from various industrial waters. Batch adsorption tests performed from 0.1 M to 5 M HCl and HNO3 systems reveal stable performance with better results in HNO3 medium. The maximum loading capacity for Pd(II) was studied in HCl as well as in HNO3. A continuous-flow experiment taking a real industrial solution revealed the feasibility of using modified CWP for the selective uptake and preconcentration of traces of palladium contained in acidic effluents. In addition, stable adsorption performance even on long exposure to γ-irradiation and selective recovery of palladium from simulated high-level liquid waste (HLW) are important outcomes of the study. 相似文献
The M4+-containing K2NiF4-type phases La0.8Sr1.2Co0.5Fe0.5O4 and La0.8Sr1.2Co0.5Mn0.5O4 have been synthesized by a sol–gel procedure and characterized by X-ray powder diffraction, thermal analysis, neutron powder diffraction and Mössbauer spectroscopy. Oxide ion vacancies are created in these materials via reduction of M4+ to M3+ and of Co3+ to Co2+. The vacancies are confined to the equatorial planes of the K2NiF4-type structure. A partial reduction of Mn3+ to Mn2+ also occurs to achieve the oxygen stoichiometry in La0.8Sr1.2Co0.5Mn0.5O3.6. La0.8Sr1.2Co0.5Fe0.5O3.65 contains Co2+ and Fe3+ ions which interact antiferromagnetically and result in noncollinear magnetic order consistent with the tetragonal symmetry. Competing ferromagnetic and antiferromagnetic interactions in La0.8Sr1.2Co0.5Fe0.5O4, La0.8Sr1.2Co0.5Mn0.5O4 and La0.8Sr1.2Co0.5Mn0.5O3.6 induce spin glass properties in these phases. 相似文献
Tungsten trioxide powder with the novel morphology was prepared via the hydrothermal method with oxalic acid as the organic inducer, the structure and shape of which were detected by X-ray diffraction (XRD), scanning electron microscopy (SEM) and BET. Furthermore, photochromic properties of the as-prepared powder samples were tested by an ultraviolet-visible spectrophotometer combined with a color difference meter. The corresponding results indicated that the induced product was still hexagonal WO3, made up... 相似文献
Metal lite : High‐resolution neutron powder diffraction data reveals that the body‐centered cubic crystal structure of lithium(0)tetraamine transforms to a simple cubic structure below 22 K. The detailed structure determinations will allow new insights into the coupled structural and electronic properties of the lightest metal.