异型磁电复合材料的一些理论与实验研究

发布时间：2018-01-28 18:21

本文关键词： 磁电效应本构方程异型磁电复合材料弯曲振动模式拉伸模式线性低频谐振　出处：《南京师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：磁电效应定义为：材料由于电场诱导的磁化改变或由磁场诱导的电极化改变。自然界中具有磁电效应的单相材料十分稀缺,并且它们的磁电响应很微弱且只能在一些极端的温度条件下才能实现。科学家们便利用铁磁材料的磁致伸缩效应和铁电材料的压电效应组合构成的复合材料产生需要的磁电效应。因此磁电复合材料的磁电效应是通过界面之间的弹性耦合导致的乘积效应引起。这种复合材料有着丰富的应用前景,包括低频下存在的巨大磁电效应,弯曲和机电频率下磁电耦合的增强,静电场和静磁场下对铁性体序参量的调控,等。这类磁电复合材料在磁场传感器,信号处理设备,和能量收集器的应用已见诸报导。研究较多的多铁性磁电复合材料主要有以下几种模型：0-3型颗粒复合材料,2-2型层状复合材料和1-3型纤维复合材料。这些模型的提出与制备使得磁电复合材料的磁电响应有了重大的突破。此后物理学家们又提出了相应的理论模型来解释实验中观察到的现象。其中研究较为广泛的理论模型有基于弹性力学和电磁学理论的弹性力学解法和基于格林函数的多散射解法以及微观力学解法。本文首先对最近引起较多关注的异型磁电复合材料的研究进展做了一些简要的介绍。通过对前人研究成果的总结和笔者对异型磁电复合材料的理解设计了一种较为新颖的异型磁电复合材料。样品由压电材料Pb(Zr0.52Ti0.48)03(PZT-5H)口铁磁材料锰锌铁氧体(Mn-Zn ferrites)组成。一共制作了4组样品进行对照试验。新设计的异型磁电复合材料更加容易发生弯曲应变,并且材料在弯曲振动模式下的弯曲振动频率很低。样品的磁电电压系数在磁场强度较低时随磁场强度的增大呈近乎线性的变化。笔者的其中一个样品在零偏置磁场下交流磁场频率为271 Hz时,磁电电压系数为6.938V/cm Oe;当将直流磁场调整为136 Oe时,一个样品在谐振频率256 Hz时的磁电电压系数可以高达113 V/cm Oe。由此笔者在很低的频率下实现了较大的磁电响应,这为样品在未来的磁电多功能材料中的应用提供了可能。最后笔者理论探讨了弯曲模式下磁电效应的产生机制,并得出在应力大小相等的情况下,弯曲模式的磁电响应大于拉伸模式。
[Abstract]:Magnetoelectric effect is defined as magnetization change induced by electric field or electrode change induced by magnetic field. Single phase material with magnetoelectric effect is very rare in nature. And their magnetoelectric response is very weak and can only be realized under some extreme temperature conditions. Scientists use the combination of the magnetostrictive effect of ferromagnetic materials and the piezoelectric effect of ferroelectric materials to produce composite materials. Therefore, the magnetoelectric effect of magnetoelectric composite is caused by the product effect caused by elastic coupling between interfaces. It includes the large magnetoelectric effect at low frequency, the enhancement of magnetoelectric coupling at the bending and electromechanical frequencies, the regulation of the order parameters of the ferroelectric body in the electrostatic field and the static magnetic field, etc. The magnetoelectric composite materials are used in the magnetic field sensor. The applications of signal processing equipment and energy collector have been reported. 2-2 laminated composites and 1-3 fiber composites. These models have made a great breakthrough in the magnetoelectric response of magnetoelectric composites. Then physicists put forward the corresponding theoretical models. The widely studied theoretical models include elastic mechanics solution based on elastic mechanics and electromagnetism theory, multiple scattering solution based on Green's function and micromechanics solution. First of all, this paper briefly introduces the research progress of irregular magnetoelectric composite materials which have attracted more attention recently. Through the summary of previous research results and the author's understanding of irregular magnetoelectric composites, a new kind of special magnetoelectric composites is designed. Novel heterogeneous magnetoelectric composites-samples from piezoelectric materials PBB. Zr0.52Ti0.48O03 (PZT-5H) ferromagnetic material Mn-Zn ferrite). A total of 4 groups of samples were prepared for controlled test. The newly designed special magnetoelectric composite materials are more prone to bending strain. When the magnetic field intensity is low, the magnetoelectric voltage coefficient of the sample changes linearly with the increase of the magnetic field intensity. One of the samples has zero bias magnetic field, and the bending vibration frequency of the material is very low in the bending vibration mode, and the magnetoelectric voltage coefficient changes linearly with the increase of the magnetic field intensity when the magnetic field intensity is low. The frequency of AC magnetic field is 271. At Hz. The magnetoelectric voltage coefficient is 6.938 V / cm Oe; When the DC magnetic field is adjusted to 136 Oe. The magnetoelectric voltage coefficient of a sample can be as high as 113 V / cm Oe at a resonant frequency of 256 Hz. This provides the possibility for the application of the sample in the future magnetoelectric multifunctional materials. Finally, the mechanism of magnetoelectric effect in bending mode is discussed theoretically, and the results show that the stress is equal. The magnetoelectric response of bending mode is larger than that of tensile mode.
【学位授予单位】：南京师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

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