resumo
Polycrystalline BiFeO3 and Bi0.90R0.10)Fe0.95Sc0.05O3 [R=La, Nd] ceramics were synthesized by solid-state reaction method. XRD studies confirmed the formation of single-phase compositions. The particle sizes obtained from XRD data were 43, 31 and 30 nm for BFO, BLFSO and BNFSO, respectively. Dielectric studies revealed anomalies around 200 degrees C and near the Neel temperature. The latter is attributed to the phase transition as an influence of vanishing magnetic order on the electric order usually observed in magneto-electric ordered systems. Complex impedance spectroscopy (CIS) technique was utilized to investigate the intra- and inter-granular contributions to the impedance in the studied compositions as a function of temperature and frequency. CIS studies revealed that the electrical relaxation process was temperature dependent and non-Debye type. AC conductivity studies revealed that conductivity in samples was mainly due to the hopping of oxygen vacancy between the oxidation states (Fe3+/Fe2+) of iron. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.
palavras-chave
BIFEO3 THIN-FILMS; FERROELECTRIC PROPERTIES; DOPED BIFEO3; RARE-EARTH; RELAXATION; CRYSTAL; PURE
categoria
Materials Science
autores
Coondoo, I; Panwar, N; Rafiq, MA; Puli, VS; Rafiq, MN; Katiyar, RS
nossos autores
Indrani Coondoo
Investigador Júnior
Muhammad Asif Rafiq
Estudante de doutoramentoagradecimentos
One of the authors (I.C.) would like to thank the Portuguese Foundation for Science and Technology (FCT) for the Postdoctoral Grant [No. SFRH/BPD/81032/2011].