Dielectric spectroscopy and magnetometry investigation of Gd-doped strontium titanate ceramics
authors Tkach, A; Amaral, JS; Vitor, SAB; Vilarinho, PM
nationality International
journal JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
author keywords SrTiO3; Doping; Dielectric relaxation; High-permittivity ceramics; Paramagnetism
keywords THERMOELECTRIC PERFORMANCE; SRTIO3; RELAXATION; SR1-XCAXTIO3; BI-SRTIO3; RELAXOR; IONS
abstract Structural, dielectric and magnetic properties of dense Gd-doped strontium titanate ceramics prepared by the conventional mixed oxide method are studied. Lattice parameter is found to decrease linearly in the Sr1-1.5xGd xTiO3 system, confirming the incorporation of Gd onto the Sr site of the perovskite lattice of strontium titanate up to x=0.05. Real and imaginary parts of the dielectric permittivity of Sr1-1.5xGd xTiO(3) ceramics exhibit a relaxation between 100 Hz and 1 MHz in the temperature range of 17-261k, slightly shifting to higher temperatures with increasing Gd content. Such dielectric behaviour is attributed to the relaxation of individual dipoles formed by off-centre displacement of Gd3+ ions on Sr sites in a highly polarizable lattice of strontium titanate. Other dielectric relaxations observed in Sr(1-1.5)xGd xTiO(3) from 125 to 300K are attributed to the oxygen vacancy related mechanisms. No magnetic anomaly but paramagnetic behaviour is observed for Sr1-1.5xGd xTiO(3) ceramics, indicating an absence of the magnetic order and hence magnetoelectric coupling.(C) 2017 Elsevier Ltd. All rights reserved.
publisher ELSEVIER SCI LTD
issn 0955-2219
isbn 1873-619X
year published 2017
volume 37
issue 6
beginning page 2391
ending page 2397
digital object identifier (doi) 10.1016/j.jeurceramsoc.2017.02.011
web of science category Materials Science, Ceramics
subject category Materials Science
unique article identifier WOS:000397359300009

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