@conference{
author = "Radojković, Aleksandar and Luković Golić, Danijela and JOVIĆ ORSINI, Nataša and Ćirković, Jovana and Branković, Zorica and Branković, Goran",
year = "2022",
abstract = "BiFeO3 is one of the few multiferroic perovskites that exhibits magnetic and ferroelectric properties
at room temperature. However, it is also distinguished by high leakage current, low remnant electric
and magnetic polarization, and high electric coercive field. These features keep it away from any practical
use in electronics. Therefore, many attempts have been made to improve the properties of BiFeO3 by
Bi- or Fe-site doping or by both. Previous investigations suggest that doping with Nbat Fe-site can
positively affect the magnetic behavior of BiFeO3 and decrease the leakage current.
In this study, various cation substitutions at Bi-site (La3+, Eu3+) and Fe-site (Nb5+, Zr4+) were examined
to investigate their possible synergism and benefit for the ferroelectric properties. The role of the cations
with higher valence is to suppress the formation of structural defects during synthesis, such as oxygen
and bismuth vacancies. These defects are responsible for high leakage currents and, consequently, low
breakdown voltages characteristic of the pure BiFeO3. On the other hand, rare earth cations at the Bisite
usually enable densification of the ceramics in a wider range of temperatures, preventing bismuth
loss and forming defects and secondary phases during sintering. However, do pant concentrations above
10–15mol% may give rise to transition from polar, rhombohedral (R3c) to non-polar, orthorhombic
(Pnma) symmetry.
The carefully selected compositions of doped BiFeO3 were synthesized by a simple hydro-evaporation
method. The ceramics samples were characterized using X-ray diffraction (XRD) analysis, scanning
electron microscopy (SEM), and polarization techniques, including leakage current measurements.
Although the introduction of Nb5+or Zr4+decreased the leakage current, they surprisingly deteriorated
the ferroelectric properties even at concentrations as low as 1 mol%. This effect was more pronounced for
the samples containing Nb. On the contrary, both La3+ and Eu3+ (incorporated at the Bi-site) improved
the ferroelectric properties as their concentrations increased. The La-doped samples exhibited higher
remnant electric polarizations at observed electric fields. The highest remnant electric polarization of31.9
μC/cm2at 150 kV/cm was measured for Bi0.85La0.15Fe0.998Zr0.002O3, indicating the synergetic
effect of La3+ and Zr4+, which is limited to very low Zr4+concentrations.",
publisher = "Linkin Science Pvt. Ltd",
journal = "5TH EDITION OF NANOTECHNOLOGY, NANOMEDICINE & OPTICS PHOTONICS HYBRID CONFERENCE",
title = "Ferroelectric properties of BiFeO3 ceramics with cation substitutions at Bi-site (La3+, Eu3+) and Fe-site (Nb5+, Zr4+)",
pages = "10",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_1738"
}
