Please use this identifier to cite or link to this item:
Type: Artigo
Title: Physical Properties Of Sr2feiro6 And Sr1.2la0.8feiro6 Double Perovskites Obtained By A New Synthesis Route
Author: Bufaical
Leandro; Coutrim
Leandro T.; Santos
Tatiane O.; Terashita
Hirotoshi; Jesus
Camilo B. R.; Pagliuso
Pascoal G.; Bittar
Eduardo M.
Abstract: Previous works on Sr2-xLaxFeIrO6 double perovskite (DP) series reported a possible ferromagnetic transition at T similar to 700 K for the x = 0.8 concentration, for which was observed the presence of spurious Fe2O3 phase. In order to prevent the formation of this impurity phase and check if this high temperature magnetic transition is intrinsic of the material, different synthesis routes became necessary. In this work, polycrystalline samples of Sr2-xLaxFeIrO6 (x = 0.0 and 0.8) have been synthesized by solid state reaction using a new heating treatment. The sample's properties were investigated by synchrotron x-ray powder diffraction (SXRD), transmission electron microscopy (TEM), magnetic susceptibility, specific heat and electrical resistivity, and compared with the previously reported results. The SXRD data revealed a structural transition induced by La to Sr substitution (I2/m <-> P2(1)/n). Moreover, it was not detected the presence of Fe2O3 on the samples obtained by the new route, which might be related to the absence of high temperature magnetic ordering. The magnetometry results indicated the emergence of Ir4+ with La doping, being corroborated by specific heat measurements which suggest Fe3+/Ir5+ and Fe3+/Ir4+ configurations for x = 0.0 and 0.8 compounds, respectively. Temperature dependent electrical resistivity measurements showed that Sr2+ to La3+ substitution leads to a decrease of electrical resistivity, possibly associated with the increase in the number of Ir valence electrons. (C) 2016 Elsevier B.V. All rights reserved.
Subject: Magnetic Materials
Heat Treatment
Crystal Structure
Magnetic Properties
Electrical Properties
Specific Heat
Editor: Elsevier Science SA
Rights: fechado
Identifier DOI: 10.1016/j.matchemphys.2016.07.057
Date Issue: 2016
Appears in Collections:Unicamp - Artigos e Outros Documentos

Files in This Item:
File SizeFormat 
000383524900056.pdf1.21 MBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.