Synthesis and refinement of the crystal structure of the Li₆ZnZr₃O₁₀ complex oxide

Abstract

En los óxidos cerámicos complejos es imprescindible determinar la estructura cristalina para conocer el ordenamiento ato mico y predecir propiedades, principalmente por la conducción del ion litio en la red cristalina. Se sintetizo una nueva fase Li₆ZnZr₃O₁₀, por reacciones químicas en estado sólido, obtenida a 1250°C/45 min. La cinética de la reacción fue seguida por difracción de rayos –X de polvos. Los datos obtenidos por refinamiento Rietveld para esta celda monoclínica resultaron: a = 8.1944, b = 5.9778, c = 5.0360; α = γ = 90°, β = 96.587°; Vol. = 246.7 cm₃, M = 540.7 g/mol, Dx = 4.2 g/cm₃, grupo espacial C2/c (No. 15), R = 0.033 para 32 reflexiones. Las longitudes de enlace Li-O son de 2.10(1) Å, 2.44(15) A; y Zn, Zr-O de 2.11(1) Å y 2.13(15) Å. Rp = 3.84%, Rwp = 4.56%, Ri = 13.45%, Rexp = 1.72%. La estructura es derivada de la sal de roca parcialmente ordenada, relacionada con la estructura ordenada Li₂ZrO₃.

In complex ceramic oxides, it is essential to determine the crystalline structure to know the atomic order and predict properties, mainly by conducting the lithium ion in the crystalline network. A new phase Li₆ZnZr₃O₁₀ was synthesized by chemical reactions in solid state, obtained at 1250°C/45 min. The reaction kinetics was followed by X-ray powder diffraction. The data obtained by Rietveld refinement for this monoclinic cell were: a = 8.1944, b = 5.9778, c = 5.0360; α = γ 90°, β = 96.587°; Vol. = 246.7 cm₃, M = 540.7 g/mol, Dx = 2.2 g/cm₃, space group C2/c (No. 15), R = 0.033 for 32 reflections, Li-O bond lengths are 2.10(1) Å and 2.44 (15) Å, and Zn, Zr-O are 2.11 (1) Å and 2.13(15) Å. Rp = 3.84%, Rwp = 4.56%, Ri = 13.45%, Rexp = 1.72%. Structure has a partially ordered rock salt structure related to the ordered structure of Li₂ZrO₃.