# Effect of synthesis route on the structure of $Nd_3-x}Ba_{3+x}Cu_6O_{14-2}_\delta$ (x=0, 1) system: a neutron diffraction study

Kini, NS and Shivashankar, SA and Umarji, AM and Yelon, WB and Malik, SK (2002) Effect of synthesis route on the structure of $Nd_3-x}Ba_{3+x}Cu_6O_{14-2}_\delta$ (x=0, 1) system: a neutron diffraction study. In: Solid State Communications, 122 (1-2). pp. 99-104.

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## Abstract

Structural studies on $Nd_{3-x}Ba_{3+x}Cu_6O_{14-2}_\delta$ with 0≤x≤1 were carried out by Rietveld refinement procedure using neutron diffraction data. The composition x=1 was prepared both by the solid-state method and the nitrate-decomposition method. Quantitative multiphase analysis coupled with variation in the method of synthesis has shown conclusively that Nd did substitute for Ba even in a stoichiometric composition $NdBa_2Cu_3O_{7 - \delta }$ , irrespective of the method of synthesis. The fractional atomic substitution of Nd at the Ba site has been determined to be about 15%. The composition x=0, synthesised by the nitrate-decomposition method, has been found to be tetragonal with the space group P4/mmm. Nd has been found to substitute for Ba according to $Nd(Ba_{0.75}Nd_{0.25})_2Cu_3O_{7 - \delta}$ and no random distribution of cations has been found along the c-direction. The observed tetragonality has been attributed to the additional oxygen taken into the basal (001) plane due to the substitution of trivalent Nd at the divalent Ba site.

Item Type: Journal Article Copyright of this article belongs to Elsevier. High-Tc superconductors;Crystal structure and symmetry;Phase transitions;Neutron scattering Division of Chemical Sciences > Materials Research Centre 02 Jun 2006 19 Sep 2010 04:29 http://eprints.iisc.ernet.in/id/eprint/7500