Synthesis and Structural Characterization of Lu1-xSrxCr0.5Fe0.5O3 (0 ≤ x≤1) perovskites

FLORENCIA LURGO; SILVINA LIMANDRI; GERMÁN TIRAO; RAÚL CARBONIO

Córdoba

Simposio; International Symposium on Radiation Physics (ISRP-14); 2018

International Radiation Physics Society (IRPS)

Rare earth perovskites of an RMO3composition, where R is a lanthanide and M is Fe, Cr or Mn, have been underexhaustive study for several decades. This is because materials with transitionmetals and rare earth ion (with unpaired d and f electrons, respectively) showa variety of striking effects resulting from the coupling between the twomagnetic sublattices.The perovskite family Lu1-xSrxM0.5Fe0.5O3(0 ≤ x ≤1) with M = Cr or Mn, have been synthesized and characterized. The sampleswere prepared in polycrystalline form by a wet chemical method. A very reactiveprecursor was prepared starting from an aqueous solution of the metal ions andcitric acid. A systematic study of the crystal structure was performed by X-raypowder diffraction (XRPD) and emission spectroscopy (XES). The XRPD data of Lu1-xSrxCr0.5Fe0.5O3(0 ≤ x ≤1) were correctly refinedusing Pbnm orthorombic unit cell, but from x=0.2 an impurity appears: SrCrO41.This is because, the SrCrO3 perovskite can only be synthetized athigh pressures (65-70 kbar)2.On the contrary, the family Lu1-xSrxMn0.5Fe0.5O3(0 ≤ x ≤1) was obtained pure andwas refined using P63/mmc or P63cm (depending on the composition of Sr)hexagonal unit cell. Taking into account that the R site is occupied by Lu3+and Sr2+ cations, high resolution XES is used to determine theoxidation state of the transition metal cations in the M site of the perovskite. Thisinformation can be obtained by measuring changes in some spectral features,such as energy shifts, possible satellite lines, line shapes and relativeintensities. For 3d transition elements, the high-resolution Kβ spectrum showsa clear sensitivity to the chemical environment3. These spectra weremeasured using a non-conventional spectrometer with conventional X-ray sources4. Keywords: Perovskite, XRPD, Highresolution XES. [1] R.W. Berg, Proceedings of the 17thinternational Symposium on materials science (1996), 175-180.[2] E. Castillo Martinez, A. Duran, M.A. Alario-Franco, J. of Solid StateChemistry 181, (2008), 895-904.[3] E. Gallo, F. Bonino, J.C. Swarbrick, T. Petrenko, A. Piovano, S.Bordiga, D. Gianolio, E. Groppo, F. Neese, C. Lamberti, P. Glatzel, Chem. Phys.Chem. 14, (2013) 79?83.[4] G. Tirao, S. Ceppi, A.L. Cappelletti, E.V. Pannunzio Miner. J. Phys.Chem. Solids 71, (2010), 199?205.