Lu1-xSrxCr0.5Fe0.5O3 (0 ≤ x≤1) perovskites: X-Ray diffraction and emission spectroscopy studies.

FLORENCIA LURGO; SILVINA LIMANDRI; GERMÁN TIRAO; RAÚL CARBONIO

Pucón

Conferencia; XVI Conferencia Latinoamericana de Análisis por Técnicas de Rayos X ?SARX-; 2018

Univerisdad de la Frontera

Lu1-xSrxM0.5Fe0.5O3(0 ≤ x ≤1) PEROVSKITESWITH M = Cr or Mn: X-RAYPOWDER DIFFRACTION AND EMISSION SPECTROSCOPY STUDIESFlorencia E. Lurgo1*, Silvina Limandri 2,Germán Tirao 2and Raúl E. Carbonio 1.1 INFIQC(CONICET- UNC), Departamento de Fisicoquímica, Facultad de Ciencias Quimicas,Universidad Nacional de Cordoba, Haya de la Torre Esq. Medina Allende, CiudadUniversitaria, X5000HUA Córdoba, Argentina.2 Facultad de Matemática, Astronomía, Física y Computación, UniversidadNacional de Córdoba e Instituto de Física Enrique Gaviola (IFEG-CONICET),Ciudad Universitaria, X5000HUA Córdoba, Argentina. *florencialurgo@gmail.comABSTRACTThe perovskite family Lu1-xSrxM0.5Fe0.5O3(0≤ x ≤1) with M = Cr or Mn, have beensynthesized and characterized. The samples were prepared in polycrystallineform by a wet chemical method. A very reactive precursor was prepared startingfrom an aqueous solution of the metal ions and citric acid. A systematic studyof the crystal structure was performed by X-ray powder diffraction (XRPD) andemission spectroscopy (XES). The XRPD data of Lu1-xSrxCr0.5Fe0.5O3(0≤ x ≤1) were correctly refined using Pbnm orthorombic unit cell, butfrom x=0.2 an impurity appears: SrCrO4. This is because, the SrCrO3perovskite can only be synthetized at high pressures (65-70 kbar). On thecontrary, the family Lu1-xSrxMn0.5Fe0.5O3(0≤ x ≤1) was obtained pure and was refined using P63/mmc or P63cm(depending on the composition of Sr) hexagonal unit cell. Taking into accountthat the R site is occupied by Lu3+ and Sr2+ cations,high resolution XES is used to determine the oxidation state of the transitionmetal cations in the M site of the perovskite and the impurity, with Cr6+cations. This information can be obtained by measuring changes in some spectralfeatures, such as energy shifts, possible satellite lines, line shapes andrelative intensities. For 3d transition elements, the high-resolution Kβspectrum shows a clear sensitivity to the chemical environment. These spectrawere measured using a non-conventional spectrometer with conventional X-raysources. Keywords:perovskite; XRPD; XES.