【作者】 李杨；

【导师】 杨晓非； 陈实；

【作者基本信息】 华中科技大学 ， 微电子学与固体电子学， 2012， 硕士

【摘要】 磁电效应是材料在磁场的作用下产生电极化（正磁电效应），或者在电场的作用下产生诱发磁化（逆磁电效应）的现象。具有磁电效应的材料称为磁电材料，其磁电转化效率通常用磁电电压系数来描述。基于磁电效应的磁电传感器，具有灵敏度和分辨力高、响应频率范围宽、室温工作、被动探测、功耗低以及制备工艺简单等特点，在地磁场、生物磁场等pTesla（10-12T）甚至f Tesla（10-15T）级微弱磁场的测量领域表现出非常好的应用前景。本文以Push-Pull工作模式的磁电层合结构为研究对象，从理论和实验两个方面研究了其磁电输出响应特性与偏置磁场、交变激励频率的关系。理论方面，以―等效电路法‖为基础，考虑与外磁场的关系，给出了低频时磁电层合结构的磁电内禀性质表达式，并讨论了磁电层合结构在谐振状态时的磁电转换及能量损耗；实验方面，搭建了磁电效应测试系统，采用动态法对磁电层合结构样品的磁电输出响应进行了测量，将得到的实验结果与理论推导结果进行对比，两者符合得较好。本文创新之处在于对磁电层合结构的磁场传感器相关各项基本参数进行了测试与评估。测试结果显示，Push-Pull型三层磁电层合结构具备较高的灵敏度和较低的背景噪声，分辨率可达到nTesla（10-9T）量级，但输出线性度还有待提高。设计并实现了磁电传感器专用信号处理电路。在Push-Pull型三层磁电层合结构基础上，引入磁致伸缩材料Metglas，得到五层磁电层合结构，显著提高了原磁电层合结构的输出响应，并研究了Metglas层厚度与磁电输出响应的关系，发现当Metglas层厚度为150μm时，五层磁电层合结构具有最大的磁电响应Emax=1.2V/cmOe（f=1kHz），该结果是原三层磁电层合结构的1.33倍。通过改变Metglas层的厚度，可以控制该五层磁电层合结构的输出响应大小及其最佳工作偏置磁场，这一特性在磁电传感器的应用中具备一定的实际意义。更多还原

【Abstract】 Magnetoelectric(ME) effect, as can be detected in the ME composite materials, is aphenomenon of polarization under the exerting of magnetic field, or induced magnetizationunder the exerting of electric field, which is a ME conversion. Its efficiency can bedescribed by a parameter named ME voltage coefficient. Magnetic sensors based on MEeffect, which exhibit significant application promise in the realms of accurate detection ofpico-Tesla (10-12T) and even femto-Tesla (10-15T) magnetic field such as geomagneticfield and biomagnetic field, simultaneously have excellent characters of high sensitivity andresolution, wide frequency response range, low power consumption, simple progressingtechnology and could be available at room temperature as well as realize passive detection.In this paper, taking the ME laminate composites of Push-Pull mode into consideration,the relationship between ME response characteristic and bias magnetic field as well as ACexcitation frequency was investigated. Theoretically, based on the―equivalent circuitmethod‖, the formula of ME voltage response to bias magnetic field at low frequency,which is the intrinsic property of the materials, was obtained; the ME response and relatedenergy consumption at resonant frequency were discussed. Experimentally, ME effecttesting system was established; the Push-Pull mode ME laminate sample was tested throughdynamic method. The results from both parts matched well.The highlight of this research is the test and evaluation work on the parameters of MElaminate sample related with magnetic sensors. The results showed that the triple-layer MElaminate sample of Push-Pull mode had high sensitivity and low background noise, whichmade the resolution could reach nTesla (10-9T) level, while the linearity of the ME laminatesample was to be inproved. The specialized signal processing circuit for ME sensor wasalso designed and manufactured. Based on the triple-layer ME laminate sample ofPush-Pull mode, Metglas was incorporated to obtain the five-layer ME laminate sample,which results in an enhanced ME response. The increase in Metglas thickness significantlyinfluences the ME response as well. It has been found that a five-layer ME laminate samplewith six sheets of Metglas (150μm thick) on both sides of the Terfenol-D layers had maximum magnitude of ME voltage coefficient of about1.2V/cm Oe which was notablyhigher than similar structures with other different Metglas thickness and was1.33timeslarger than the ME response of the triple-layer ME laminate sample. We can control theME response and optimal bias magnetic field of this kind of five-layer ME laminatecomposites by altering the thickness of Metglas layers, which proves practical significancein the application of ME sensor.更多还原