Selection and Optimization of a K0.5Na0.5NbO3-Based Material for Environmentally-Friendly Magnetoelectric Composites

Abstract

Li- and Ta-modified K 0.5 Na 0.5 NbO 3 compounds are among the most promising lead-free ferroelectrics for high-sensitivity piezoelectric ceramic materials, and are potentially capable of replacing Pb(Zr,Ti)O 3 . They are also being investigated as piezoelectric components in environmentally friendly magnetoelectric composites. However, most suitable modifications for this application have not been identified. We report here a simulation study of how the magnetoelectric voltage responses of layered composite structures based on Li x (K 0.5 Na 0.5 ) 1 − x Nb 1 − y Ta y O 3 varies with the chemical composition of the piezoelectric. Instead of relying on material coefficients from the literature, which would have required using different sources, an ad hoc set of materials was prepared. This demanded tailoring preparation by conventional means to obtain dense ceramics while controlling alkali volatilization, perovskite phase and microstructure, as well as characterizing their dielectric, elastic and electromechanical properties. This provided the set of relevant material coefficients as a function of composition, which was used to obtain the magnetoelectric responses of model layered structures including a reference magnetostrictive spinel oxide by simulation. The piezoelectric material leading to the highest magnetoelectric coefficient was identified, and shown to be different to that showing the highest piezoelectric coefficient. This reflects the dependence of the magnetoelectric response on all material coefficients, along with the complex interplay between composition, processing and properties in K 0.5 Na 0.5 NbO 3 -based ceramics.

Effects of Sb on structure, micro structure and electrical characteristics of Sb-modified (K0.41Na0.59)NbO3 ceramics

“…The (1.32 Å) that are present in the A-site, as shown in the ABO3 model [5,20,[22][23][24]. The results agreed well with previously reported results Jiang et al…”

Structural and magnetic characterization of BaTiO3–BaFe12O19 bilayer thin films: Interface effects on the magnetic properties of barium hexaferrite layer

“…For example, the study of the materials referred to as multiferroics, which combines at least two ferroic orders (ferroelectric, ferromagnetic, or ferroelastic) [1,4,6] has taken great interest because in some of these MF materials, the magnetization can be controlled by an applied electric field, and vice versa, the electric polarization can be controlled by an applied magnetic field. This phenomenon, called magnetoelectric effect (ME) [7,8], is several times greater in the composite MF that in intrinsic MF [9,10]. It is in this sense that the MF bilayer compounds have recently gained great interest.…”

Component fraction effect on microstructure and properties of CoFe2O4−K0.5Na0.5NbO3 composites

“…3 So far, there were only limited numbers of studies on the CFO−KNN particulate composites, although pure or doped KNN and CFO have each been used frequently for making ME composites with other counterparts. 3,6,[11][12][13][14][15] Recently, computer simulation revealed that the composites made of KNN-based ferroelectrics and CFO-based ferrimagnets may potentially have high ME coefficients. 15…”

“…3,6,[11][12][13][14][15] Recently, computer simulation revealed that the composites made of KNN-based ferroelectrics and CFO-based ferrimagnets may potentially have high ME coefficients. 15…”