Observation of magnetoelectric coupling and local piezoresponse in modified (Na_0.5Bi_0.5)TiO₃–BaTiO₃–CoFe₂O₄ lead-free composites

Abstract

Lead-free particulate multiferroic composites of [0.94(Na0.5Bi0.5)TiO3-0.06 BaTiO3]:(Co0.6Zn0.4)(Fe1.7Mn0.3)O4 were synthesized and magnetoelectric (ME) properties were studied. X-ray diffraction and microstructural studies indicated the formation of a two-phase composite system without any impurities. The shift of Raman modes corresponding to ferroelectric and ferrite phases was assigned to the induced strain amid the formation of a two-phase system, in relation to the fraction of each phase in the samples. A strong local piezoresponse and hysteresis loops observed for composites established the ferroelectric properties at a nanoscale. Magnetostriction measurements revealed values of λ11 = -10.4 and λ12 = 5.3 ppm and piezomagnetic coefficient dλ11/dH = -0.0087 ppm Oe(-1) at 0.45 kOe for a composite with a ferrite concentration of 35 mol%. A maximum change of 18.5% in magnetization after electrical poling indicates a strong magnetoelectric response of the present composites followed by a direct ME coefficient of 8.2 mV cm(-1) Oe(-1). Our studies point to the fact that the present multiferroic composites having strong ME coupling are useful for lead-free electronic applications.

Structural, Magnetic, Dielectric and Energy Storage Analysis of CoFe2O4@BaTiO3 and BaTiO3@CoFe2O4 Core-Shell Nano- Composites

“…Figure 3(a) clearly shows tetragonal BTO nanoparticles with particle size ~ 49 nm which is accordance with the XRD results. ) is analogous to the previous reported results [19]. Such type of behaviour in BTO nanoparticles isattributedtopresence of defects as oxygen vacancies on the grains surfaces.…”

Composition‐Dependent Microstructures and Properties of La‐, Zn‐, and Cr‐Modified 0.675BiFeO3–0.325BaTiO3 Ceramics

“…Obviously, the coercive magnetic field of BF–BT:Cr increases from 0.40 T before electrical poling to 0.45 T after electrical poling, which can be attributed to the fact that the electrical poling produces considerable strain in ferroelectric BF–BT:Zn and BF–BT:Cr matrixes. The strain can create hard axis along the poling direction . However, from the almost overlapped M–H loops of BF–BT:Zn before and after electrical poling [Fig.…”

“…The strain can create hard axis along the poling direction. [58][59][60] However, from the almost overlapped M-H loops of BF-BT:Zn before and after electrical poling [ Fig. 7(b) and the inset of partly enlarged curve], it is concluded that the BF-BT:Zn has very low magnetoelectric coupling.…”

Lattice Defects Induce Multiferroic Responses in Ce, La‐Substituted BaFe0.01Ti0.99O3 Nanostructures

“…The maximum value of α ME is 62.65 and 49.79 mV/cm Oe, respectively, measured for BFTO:Ce and BFTO:La samples. This measurement of α ME indicates an improvement than BTO based multiferroic systems …”