TITLE:
Structural, Magnetic and Transport Properties of Gd and Cu Co-Doped BiFeO3 Multiferroics
AUTHORS:
Sajal Chandra Mazumdar, Sanjib Datta, Farhad Alam
KEYWORDS:
X-Ray Diffraction, Permeability, Dielectric Constant, Conductivity
JOURNAL NAME:
Journal of Applied Mathematics and Physics,
Vol.10 No.6,
June
30,
2022
ABSTRACT: The novel polycrystalline Bi0.85Gd0.15CuxFe1-xO3 (x = 0, 0.025, 0.05, 0.075, 0.10) multiferroics are synthesized by the usual solid-state reaction route. The synthesis of the desired phase has been verified by the X-ray Diffraction (XRD) patterns. With major structural phases, few traces of secondary phases of Bi2Fe4O9 and Bi25FeO40 appear for all the compositions. A discontinuous series of structural changes with varying compositions are observed for the doped samples. The bulk density (ρB) increases with Cu content reaches the highest at x = 0.05 and then declines. The complex initial permeability and dielectric characterizations are performed by Wayne Kerr Impedance Analyzer. The x = 0.05 samples having maximum density exhibit the highest permeability (μi’) implying a close relation between μi’ and the density. The reduction of μi’ at higher Cu concentration is due to the low density of the samples associated with the increased intragranular pores. The dielectric constant (ε’) is measured against frequency in the range 1 kHz - 10 MHz. It is perceived that ε’ falls with the rise in frequency up to 100 kHz. This dielectric dispersion is observed at a lower frequency as a result of interfacial polarization outlined by Maxwell-Wagner. The maximum ε’ is obtained for x = 0.025 composition. In the low-frequency range, the AC conductivity σAC is practically independent of frequency and resembles the DC conductivity (σDC). In the vicinity of high frequency recognized as the hopping region, σAC rises since the conductive grains are more active at high frequencies. The co-doping with Gd and Cu in BiFeO3 ceramics enhances the magnetic and dielectric properties of the ceramics and hence can be utilized for fabricating multifunctional devices.