摘 要

将商业购买的Terfenol-D环插入PZT圆柱环内，形成PZT/Terfenol-D双层圆柱复合结构的磁电传感器，充分利用法向应力耦合代替传统平面层状结构中的切向应力耦合，得到改善的磁电耦合。实验结果表明,当偏置磁场沿着轴向而交流磁场沿着切向时，可得到低频下0.37 Vcm^-1Oe^-1的磁电电压系数，谐振频率46.0kHz下8.5 Vcm^-1Oe^-1的磁电电压系数。这远高于传统的平面环状结构中的结果，其原因可归结为法向应力代替切向应力耦合。在室温下，磁电电压在较宽的磁场范围10^-8lt;H_aclt;10^-5T内，不管是低频还是谐振频率下，都表现出与外加交流磁场良好的线性响应关系。而且，磁电电压在Hz~kHz的频率范围内与交流磁场频率无关。因此，圆柱环磁电复合结构中较强而稳定的切向磁电效应在涡旋磁场传感器件方面具有重要的潜在应用价值。

关键词：磁电传感器；切向磁电效应；磁电系数；谐振频率；线性响应

Abstract

Inserting commercially available Terfenol-D ring into a PZT cylindrical ring, a magnetoelectric sensor was formed based on cylindrical laminate composites of PZT and Terfenol-D. The cylindrical magnetoelectric composite structure is coupled with normal stress instead of the tangential stress coupling in conventional planar layered structures, resulting in improved magnetoelectric coupling. Strong circumferential magnetoelectric effect has been observed in cylindrical PZT/Terfenol-D composite. With dc bias along axial direction and ac magnetic field along circumferential direction, strong ME voltage is obtained as 0.37 Vcm^-1Oe^-1 at off-resonance frequency 1 kHz and as high as 8.5 Vcm^-1Oe^-1 at resonance frequency f_r=46.0kHz, which is much higher than that observed in planar ring-type ME laminate. The enhanced ME effect is attributed to improved interface mechanical coupling via normal stress. At room temperature, induced voltage from this cylindrical ME composite exhibits a near-linear response to applied ac vortex magnetic field amplitude over a wide magnetic field range of 10^-8lt;H_aclt;10^-5T both at low frequency and resonance frequency. Moreover, induced voltage has an excellent flat response to applied ac magnetic field frequency between Hz and kHz. The strong and stable circumferential ME effect in cylindrical ME laminate offers potential in vortex magnetic field sensor applications.

Key Words: magnetoelectric sensor; tangential magnetoelectric effect; magnetoelectric coefficient; resonant frequency; linear response

目录

第一章 绪论 1

1.1磁电效应和磁电材料 1

1.2磁电效应的研究现状 1

1.3.常见磁电复合材料的结构 2

1.4磁电效应的应用 2

1.5涡旋磁场传感器 3

1.6目的与意义 3

参考文献 3

第二章 基于PZT/Terfenol-D圆柱复合材料切向磁电效应的涡旋磁场传感器 5

2.1引言 5

2.2 样品制备和磁电效应测量 6

2.3结果与讨论 7

2.4本章小结 10

参考文献 11

第三章 小结与展望 13

3.1 研究成果小结 13

3.2 器件的进一步改进 13

3.3磁传感器的研究现状和未来发展趋势 13

参考文献 14

致谢 15

第一章 绪论

1.1磁电效应和磁电材料

磁电效应可以分为正磁电效应，即磁场诱导介质电极化：P=H（P为诱导电极化强度，H为外加磁场）；和逆磁电效应，即电场诱导介质磁极化：M=E，（M为磁化强度，E为外加磁电场）[1]。而磁电材料是指具有磁电效应的材料。

1.2磁电效应的研究现状

19世纪末，人们最先在单相材料中发现了磁电效应[2]。近年来，人们不仅在单相磁电材料的研究中克服许多问题[3]，获得了重大突破，而且在复合磁电材料方面的研究也有所进步。

1.2.1单相磁电材料

单相磁电材料包括磁-电材料、铁电-铁磁性材料等单相材料，和Pb（Fe_0.5Tab_0.5)O₃[4]等单相固溶体材料。据报道，南京大学已成功制备出高度绝缘的纯相BiFeO₃陶瓷[5]。

1.2.2复合磁电材料