Self-Biased Lead-Free Magnetoelectric Laminates

Abstract

Multiferroic materials possess two or more ferroic orders such as ferroelectric, ferromagnetic, or ferroelastic. Multiferroic magnetoelectric (ME) materials exhibit direct coupling between the ferroelectric and ferromagnetic order parameters. In composites, ME effect is a combination of two types of material property such as magnetostriction and piezoelectricity. On application of magnetic field, magnetostrictive phase produces strain which is transferred on to the piezoelectric phase that converts strain into electric charge. This conversion of applied magnetic field into electric field is termed as direct ME effect. On the other hand, under applied electric field piezoelectric phase produces strain which is transferred on to the magnetostrictive phase that converts it into magnetic field, termed as converse ME effect [1]. Figure 16.1 shows that ME materials exhibit cross-coupling between the applied magnetic field and electric polarization or vice versa.In general, ME materials are categorized into four groups (i) single-phase materials, (ii) 3-0 type particulate composites, (iii) 2-2 type laminate composites, and (iv) 1-3 type cylinder-matrix composites. Single-phase materials exhibiting ME effects should show two coupled-transitions: one from ferroelectric to paraelectric state, and another from ferro/ferri/antiferro-magnetic to paramagnetic state: the ME effect then arises due to coupling between the magnetic and polar sublattices. Recent investigations of single-phase multiferroics have revealed that the origin of ME effect is often associated with a particular exchange mechanism for various families of compounds such as: orbital ordering, Jahn-Teller distortion, super/ double exchange, and/or geometric magnetic frustration. Unfortunately, singlephase materials suffer from the drawback that the ME effect is extremely small at room temperature. For example, the highest ME coefficient has been reported for

Review of multi-layered magnetoelectric composite materials and devices applications

“…Classification of some of the piezoelectric materials for ME composites[46][47][48][49][50][51][52][53][54][55][56][57].…”

Leveraging the strain transfer at the interface between self-composite CoFe2O4 embedded in pre-sintered Na0.5Bi0.5TiO3 ceramics matrix for the enhancement of magnetoelectric voltage coefficient

“…The collective strain generated from the saturated domain wall motion of both CFO-b and CFO-n with more grains in the interface is also responsible for the enhanced ME coefficient values. Further, the addition of the ferrite phase may result in charge leakage through highly conducting CFO grains, which can hinder the electric poling and make the rotation of the dipoles under the applied magnetic field challenging [37]. The ME coefficient caused by the strain in the NBT-CFO particulate composites prepared with different methods are also given in table 3.…”

Polymer‐/Ceramic‐based Dielectric Composites for Energy Storage and Conversion

“…2022, 5, 486-514 and flexibility of RE-FE composites. Here, we plot the measured d 33 over the mass density and the elastic compliance against selected piezoelectric materials, [191][192][193][194][195][196][197][198][199] as shown in Figure 11e. The piezoelectric composites could have a larger specific piezoelectric constant (i.e., |d 33 |/ ρ) and higher elastic compliance than hard and soft PZT ceramics.…”

“…Data are collected from Refs. [192][193][194][195][196][197][198][199] f-g) TEM images showing Moiré fringes and the existence of PNRS. [203] Copyright © 2018, The Royal Society of Chemistry.…”

“…e) Specific piezoelectric charge coefficients vs elastic compliance for various piezoelectric materials. Data are collected from Refs [192][193][194][195][196][197][198][199]. f-g) TEM images showing Moiré fringes and the existence of PNRS [203].…”