Multiferroic coupling in nanoscale BiFeO3

Abstract

Using the results of x-ray and neutron diffraction experiments, we show that the ferroelectric polarization, in ~22 nm particles of BiFeO3, exhibits a jump by ~30% around the magnetic transition point T_N (~635 K) and a suppression by ~7% under 5T magnetic field at room temperature (<<T_N). These results confirm presence of strong multiferroic coupling even in nanoscale BiFeO3 and thus could prove to be quite useful for applications based on nanosized devices of BiFeO3.Comment: 4 pages including 4 figures and supplementary data; accepted for publication in Appl. Phys. Let

Large magnetoelectric coupling in nanoscaleBiFeO3from direct electrical measurements

“…Therefore, it seems that apart from significant intrinsic change in the ferroelectric polarization under a magnetic field, a small change can also result from change in the depolarizing field under a magnetic field. Though comparison of the extent of suppression of ferroelectric polarization under a magnetic field, noticed in neutron diffraction [20] and direct electrical measurements is hiniting at a possible influence of magnetoelectric effect of the disordered interfaces in this direct electrical measurement, a quantitative estimation of the contribution of the magnetoelectric effect at the interface on the intrinsic effect of the core of the particles requires controlled introduction of the disorder within an ordered region.…”

“…More microscopically, it occurs because of ionic displacement under a magnetic field via inverse Dzialoshinskii-Moriya exchange coupling interaction. In order to estimate the extent of ionic displacement under a magnetic field, we analyze the results obtained from Rietveld refinement of the room temperature neutron diffraction data [20] recorded under zero and 50 kOe magnetic field for nanoscale BiFeO 3 . The ionic positions for Fe and O ions in a unit cell were refined while the position of the Bi ion was kept fixed.…”

Enhancement in multiferroic and piezoelectric properties of BiFeO 3 –BaTiO 3 –Bi 0.5 Na 0.5 TiO 3 lead-free ceramics with MnO 2 addition by optimizing sintering temperature and dwell time

“…due to the coupling between ferroelectric and ferromagnetic parameters [1][2][3][4]. It has been believed that the ferroelectricity in BFO is caused by the 6s 2 lone pair electrons of Bi 3+ , while the magnetism originates from the partially filled d-orbitals of Fe [5,6].…”

Improved ferroelectricity and ferromagnetism of Eu-modified BiFeO3–BaTiO3 lead-free multiferroic ceramics

“…Multiferroic material is one of the most important multifunction materials and has been investigated extensively [1][2][3][4]. As a rare single-phase room temperature multiferroic material, bismuth ferrite (BiFeO 3 , BFO) has attracted considerable attention in recent years.…”