Preparation, structural analysis and dielectric properties of Bi x La1−x FeO3 perovskite

Autor: K. K. Patankar, S.A. Patil, P. B. Joshi, M. B. Kothale, Vikas L. Mathe, S. B. Kulkarni
Rok vydání: 2002
Předmět:
Zdroj: Pramana. 58:1105-1113
ISSN: 0973-7111
0304-4289
DOI: 10.1007/s12043-002-0226-x
Popis: Rare earth element substituted bismuth ferrites (BiFeO3) are of enormous importance as magnetoelectric materials. The polycrystalline samples of BixLa1−xFeO3 (x=0, 0.2, 0.4, 0.6, 0.8) were prepared by solid-state reaction using standard ceramic method. The single-phase formation of these compounds was confirmed by X-ray diffraction (XRD) studies. The samples with x=0, 0.2, 0.4, 0.6 are found to be orthorhombic while the sample with x=0.8 is triclinic. The dielectric constant (e′) and dissipation factor (tan δ) were measured in the frequency range 100 Hz to 1 MHz at room temperature and as a function of temperature at certain fixed frequencies (1 kHz, 10 kHz, 100 kHz, 1 MHz). All the samples showed dielectric dispersion. The dielectric constant with temperature shows a broad peak; the peak temperature shifts with frequency which reflects the relaxor-type behavior. The peak above 600 K in the measured temperature range corresponds to antiferromagnetic ordering temperature (Neel temperature). The broadness of the peak changes with composition. The ac conductivity as well as e′ are found to be maximum for the sample x=0.2 at room temperature.
Databáze: OpenAIRE
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