32. Neutron powder diffraction study at high temperature of the Ruddlesden Popper phase La Sr3Fe1.5Co1.5O10-d

A. ABATE; F. PRADO; A. CANEIRO

Natal

Workshop; School and Workshop on the Fundamentals of Neutron Scattering; 2013

International Institute of Physics

The crystal and oxygen defect structure of the n = 3 Ruddlesden-Popper phase LaSr3Fe1.5Co1.5O10-d have been studied by in situ high temperature neutron powder difraction in the temperature range 20 < T 900 °C in air. The analysis of the neutron difraction data revealed the presence of structural oxygen vacancies on both the O(4) sites in the (Fe/Co)O2 plane of the intermediate perovskite layer and the O(3) sites linking the octahedra along the c-axis. This result supports the oxygen ion diffusion mechanism involves the migration of vacancies around the (Fe/Co)O6 octahedron edge like in the perovskite phases [1,2]. The preceding values determined by the Rietveld method were in good agreement with those obtained by iodometric titration. The total volumetric expansion is aV/3= 26,4 (5) x 10-6K-1 and it mainly affects the perovskite block while the width of the rock salt layers remains stable with temperature