Some Theoretical And Experimental Studies On Heterogeneous Magnetoelectric Composites

Magnetoelectric effect (ME) can be defined as magnetization effect arised from induction of the electric field or electric polarization effect arised from induction of the magnetic field. Single phase magnetoelectric material in nature is rare, in addition, their magnetoelectric response is weak and only can be achieved under extreme temperature. Then scientists think that using the magnetostrictive effect of ferromagnetic materials and piezoelectric effect of ferroelectric materials is an effective way to fulfill magnetoelectric effect in compound material. The magnetoelectric effect of magnetoelectric composite materials is arised from the product effect of coupling of ferromagnetic materials and ferroelectric materials. Magnetoelectric composite materials have rich use of the characteristics, including huge ME effect under low frequency, enhanced ME effect under bending mode, the control of ferroic order parameter under electrostatic field and magnetic field. Recently many significant interesting applications of magnetoelectric composite have been reported by people, including magnetic field sensor, signal processing equipment, and energy collector.Various ME composites in different systems have been investigated in recent years, including 0-3 type particulate composites,2-2 type laminate ceramic composites and 1-3 type fiber composites. The model proposed is a major breakthrough of magnetoelectric composite material. Since then physicists put forward some corresponding theory model to explain the phenomena observed in experiments. Constitutive equation and Green’s function technique are usually used in the topic of magnetoelectric effect.At first, this paper will do some brief introduction of the study progresses of relatively hot research of special-shaped magnetoelectric composites.Then, through summarizing the research before and according to the understanding of the special-shaped magnetoelectric composite. We design a special novel magnetoelectric composite. The sample is composed of piezoelectric materials Pb(Zr0.52Ti0.48)O3 (PZT-5H) and ferroelectric materials Mn-Zn ferrites. We made 4 groups of samples to be the controlled trials. The new special magnetoelectric composite is more prone to bend, and the bending vibration frequency of materials in flexural vibration mode is very low. Magnetoelectric coefficient of one of our sample measured under alternating magnetic fields (AC) frequency of 271 Hz is 6.938 V/cmOe at zero bias field. When the DC magnetic field is adjusted to 136 Oe, magnetoelectric coefficient of one sample at the resonant frequency of 256 Hz can be as high as 11.3 V/cm Oe. From this work we can achieve large magnetoelectric response at low frequency, it provides the possibility for the sample used in magnetoelectric functional materials in the future.At last, We discuss the mechanism of magnetoelectric effect in bending mode, finding that magnetoelectric response of bending mode is greater than tensile mode under the same stress。...