Development of Bismuth Ferrite as a Piezoelectric and Multiferroic Material by Cobalt Substitution

Abstract

Bismuth ferrite (BiFeO ) is the most widely studied multiferroic material with robust ferroelectricity and antiferromagnetic ordering at room temperature. One of the possible device applications of this material is one that utilizes the ferroelectric/piezoelectric property itself such as ferroelectric memory components, actuators, and so on. Other applications are more challenging and make full use of its multiferroic property to realize novel spintronics and magnetic memory devices, which can be addressed electrically as well as magnetically. This progress report summarizes the recent attempt to control the piezoelectric and magnetic properties of BiFeO by cobalt substitution.

Enhancement of phase stability and optoelectronic performance of BiFeO3thin filmsviacation co-substitution

“…Albeit such concentrations of substitutional atoms are not identical to the experimental ones (due to the constraints imposed by the size of the adopted simulation cell, see Experimental Section for technical details) and the limitations of DFT methods to predict exact energy band gaps are well known, 65 we expect our theoretical results to be qualitatively meaningful and comparable to our experimental findings. Following previous experimental and theoretical works, 66,67 we adopted a low-symmetry rhombohedral-like phase presenting large anti-phase O 6 rotations along the three pseudo-Cartesian axes (i.e., similar to the BFO ground-state phase described by the space group R3c 39 but with lower symmetry) to perform our DFT calculations and analysis. Our sampling of all possible Fe/Co B-site arrangements compatible with the adopted simulation cell indicates that Co atoms tend to disperse homogeneously in the solution (i.e., Co nearest neighbours are Fe ions, see Fig.…”

Multifunctional nanopatterned porous bismuth ferrite thin films

“…or as a single phase multiferroic with enhanced ferroic properties for application in spintronics and magnetic memory devices, which can be addressed electrically and magnetically. 44 Moreover, nanopatterned porous films having a continuous structure of large pores are attractive structures for the development of novel and original multiferroic structures, where the magnetic behavior can be enhanced by the functionalization of the pores with a ferromagnetic material, enlarging the temperature range of application and/or increasing the magnetoelectric coupling. Additionally, due to the small band gap compared with other semiconductor materials, these nanopatterned BiFeO 3 thin films can be used as novel and effective visible-light photocatalyts, 45 in photovoltaic devices 4 and as alternative materials for energy-related applications.…”

The Experimentalist's Guide to the Cycloid, or Noncollinear Antiferromagnetism in Epitaxial BiFeO3

“…[ 228–233 ] Typical doping on the B‐site is used to modify or enhance the magnetic characteristics (notably the weak magnetic moment) and multiferroic coupling. [ 234,235 ] Finally, since the cycloid is intimately linked to the presence of the polarization, one can presume that any alteration of the latter will affect the cycloid. Indeed, this was observed in our first case study, as described next.…”