Structure property relations in BiFeO3/BaTiO3 solid solutions

Abstract

BiFeO 3 , when forming a solid solution with BaTiO3, shows structural transformations over the entire compositional range. Above 70 mole % of BiFeO3 the structure is rhombohedral and below 4 mole %, it is tetragonal. In between the structure is cubic. The ferroelectric TC decreases with increasing composition of BaTiO3 and a relatively small relaxation is observed. Impedance measurements showed a structural dependence and analysis of which has clearly shown that the capacitance observed is from the bulk of the sample. Relaxation time (τ) of BiFeO3 was estimated using the relaxation times of the intermediate compositions. Magnetization measurements showed field induced ferromagnetism. As the structure becomes cubic with increasing concentration of BaTiO3, paramagnetism sets in, as evidenced by the electron spin resonance spectra.

Piezoelectric nonlinearity and frequency dispersion of the direct piezoelectric response of BiFeO3 ceramics

“…[1][2][3] Owing to its rhombohedral structure, the ferrite has been considered as an end-member of a variety of leadfree solid solutions exhibiting morphotropic phase boundary (MPB), which is believed to be the key for obtaining high piezoelectric properties. Some recently studied systems are BiFeO 3 -REFeO 3 (RE = La, Nd, Sm, Gd, Dy), [4][5][6] BiFeO 3 -BaTiO 3 , 7,8 and BiFeO 3 -Bi(Zn 0.5 Ti 0.5 )O 3 . 9 In addition, the high T C of BiFeO 3 enables to design MPB compositions suitable for high-temperature piezoelectric applications, such as the recently emerged BiFeO 3 -PbTiO 3 .…”

Giant magnetoelectric coupling interaction in BaTiO3/BiFeO3/BaTiO3 trilayer multiferroic heterostructures

“…5 It has been very well explored that solid solutions of BFO with ferroelectric perovskite material BaTiO 3 (BTO) result in improved ferroelectric and magnetic properties. [6][7][8][9] However, there have been only few studies undertaken on epitaxial bilayer and multilayer thin films of BFO/BTO multiferroic composites. 10,11 In the layered composite thin film structures, magnetoelectric effects can be induced at the interface between two phases via strain between the two phases, change in oxygen stoichiometry, electronic correlations, interface bonding, exchange bias, and other physical phenomenon may also take place.…”

Room-temperature magnetoelectric coupling in single-phase BaTiO3-BiFeO3 system

“…[17][18][19][20][21][22][23] BaTiO 3 is a promising candidate in this respect, and (1 À x) BaTiO 3 -x BiFeO 3 solid solutions have been shown to exhibit rhombohedral (0.7 < x 1.0), pseudo-cubic (0.04 < x 0.7), and tetragonal (0 x 0.04) phases. 24 Moreover, substitution of La, Nb, and Mn in the BaTiO 3 -BiFeO 3 has been studied in order to enhance the piezoelectric properties and DC resistivity. [25][26][27][28] Recently, improved piezoelectric value of d 33 ¼ 116 pC N À1 with high DC resistivity of 2.7 Â 10 7 X m was reported in Mn-modified BaTiO 3 -BiFeO 3 ceramics by Leontsev et al 28 In parallel, several studies on BaTiO 3 -BiFeO 3 29 Generally, ME effect can be classified as direct magnetoelectric (DME) effect and converse magnetoelectric (CME) effect.…”