Progress in Dual (Piezoelectric-Magnetostrictive) Phase Magnetoelectric Sintered Composites

Abstract

The primary aims of this review article are (a) to develop the fundamental understanding of ME behavior in perovskite piezoelectric-spinel magnetostrictive composite systems, (b) to identify the role of composition, microstructural variables, phase transformations, composite geometry, and postsintering heat treatment on ME coefficient, and (c) to synthesize, characterize, and utilize the high ME coefficient composite. The desired range of ME coefficient in the sintered composite is 0.5-1 V/cm·Oe. The studies showed that the soft piezoelectric phase quantified by smaller elastic modulus, large grain size of piezoelectric phase (∼1 μm), and layered structures yields higher magnitude of ME coefficient. It is also found that postsintering thermal treatment such as annealing and aging alters the magnitude of magnetization providing an increase in the magnitude of ME coefficient. A trilayer composite was synthesized using pressure-assisted sintering with soft phase [0.9 PZT-0.1 PZN] having grain size larger than 1 μm and soft ferromagnetic phase of composition Ni 0.8 Cu 0.2 Zn 0.2 Fe 2 O 4 [NCZF]. The composite showed a high ME coefficient of 412 and 494 mV/cm·Oe after sintering and annealing, respectively. Optimized ferrite to PZT thickness ratio was found to be 5.33, providing ME coefficient of 525 mV/cm·Oe. The ME coefficient exhibited orientation dependence with respect to applied magnetic field. Multilayering the PZT layer increased the magnitude of ME coefficient to 782 mV/cm·Oe. Piezoelectric grain texturing and nanoparticulate assembly techniques were incorporated with the layered geometry. It was found that with moderate texturing, d 33 and ME coefficient reached up to 325 pC/N and 878 mV/cm·Oe, respectively. Nanoparticulate core shell assembly shows the promise for achieving large ME coefficient in the sintered composites. A systematic relationship between composition, microstructure, geometry, and properties is presented which will lead to development of high-performance magnetoelectric materials.

Giant and universal magnetoelectric coupling in soft materials and concomitant ramifications for materials science and biology

“…The magnetoelectric coefficients depicted in Fig. 2 compare well with some well-known composites, e.g., at a field of 300 Oe: A textured NCZF-PZT-PZN-NCZF trilayer system has an α of 900 mV/cm Oe, which drops to 200 at a field strength of 500 Oe [9]. In general, a direct comparison with some other claimed high magnetoelectric composites (e.g., Tefernol-D/PZT [26]) is difficult since our results are essentially frequency independent, are capable of orders of magnitude larger deformations, and finally may yield higher polarization for the same magnetoelectric coefficient.…”

“…Despite their discovery as early as in the 1950's, magnetoelectric materials remained a scientific curiosity for several decades. Single-phase, intrinsically magnetoelectric materials are only weakly so, and that too at impractically low temperatures-in fact, to date, a single-phase material that exhibits a strong enough magnetoelectric effect for roomtemperature operable technological applications has yet to be discovered [1][2][3][4][5][6][7][8][9][10]. Recent advances in fabrication methods, nanotechnology, and concurrent insights from ab initio calculations have spurred intense research in this field [1,2,11,12].…”

Biomedical applications of multifunctional magnetoelectric nanoparticles

“…The significant opportunities for using MENPs in biomedicine are attributable to their unique properties of: (1) good mechanical interfacial bonding at the magnetic and piezoelectric layers, (2) ability to transfer magnetostrictive stresses to the piezoelectric phase, and (3) the absence of substrate clamping effects on laminated thin film-structures. 48 Biocompatible NPs with these features have tremendous potential for use in on-demand drug release and control of biology.…”

Complex magnetoelectric effect in multiferroic composites: the case of PFN-PT/(Co,Ni)Fe2O4

“…A high magnetostrictive material such as CFO is usually used in these composites. In past years several ferrite-piezoelectric composites have been studied, such as CFO (or NFO)/Pb(Mg 1/3 Nb 2/3 )-PbTiO 3 [7][8][9][10][11], CFO (or NFO)/Pb(Zr,Ti)O 3 [12][13][14][15], and CFO/BaTiO 3 [16][17][18]. Conventionally, α ME is measured as a function of dc magnetic field, which shows a peak at a certain field.…”