Wide-Band Magnetoelectric Interactions in Single Crystal Multiferroic Bilayers

****非技术摘要*****能够进行磁场到电场转换的材料在各种技术中都有潜在的用途。这种磁电材料在自然界中很少，大多数材料在转换磁场时效率很低。本研究针对具有优异转化性能的人工复合材料。这种复合材料将由在磁场中变形的铁氧体板和在变形时产生电场的铁电体结合而成。磁场转换特性将在广泛的频率范围内进行研究，以获取其在消费电子、通信设备和雷达系统中的使用信息。这些项目将为各级人员提供研究培训，从高中二年级到博士后助理。****技术摘要*****计划对单晶铁氧体和铁电体双层中的宽带磁电（ME）相互作用进行综合研究。电磁耦合是由机械应力、磁致伸缩引起的机械变形和压电效应引起的电场介导的。理论预测单晶中的ME相互作用比多晶多层中的强几个数量级。主要任务和目标如下。(1)利用键合技术制备尖晶石铁氧体和压电体组成的双层材料。（ii）测量和分析ME色散特性，包括Maxwell-Wagner弛豫和低频ME效应。（iii）电、磁子系统呈现共振行为时的共振ME效应研究。人力资源开发将涉及各个层次的人员，从高中生到研究助理。ME材料是磁电存储器件、磁场传感器、电控磁器件和磁控压电器件的潜在候选材料。

****NON-TECHNICAL ABSTRACT*****Materials that are capable of magnetic field-to-electric field conversion are potentially useful for a variety of technologies. There are few such magneto-electric materials in nature and most of them have a low efficiency when converting fields. This research is aimed at artificial composite materials with excellent conversion properties. The composites will be made by bonding plates of ferrites, which deform in a magnetic field, together with ferroelectrics, which produce an electric field when deformed. The field conversion properties will be studied over a wide frequency range for information on their use in consumer electronics, communication devices, and radar systems. These projects will provide research training for personnel at all levels, from high school sophomores to post doctoral associates.**** TECHNICAL ABSTRACT*****A comprehensive research program is planned on wide-band magnetoelectric (ME) interactions in bilayers of single crystal ferrites and ferroelectrics. The electromagnetic coupling in such systems is mediated by mechanical stress: magnetostriction induced mechanical deformation and the piezoelectric effect induced electric fields. Theories predict orders of magnitude stronger ME interactions in single crystals compared to polycrystalline multilayers. The primary tasks and goals are as follows. (i) The fabrication of bilayers consisting of spinel ferrites and piezoelectrics by bonding techniques. (ii) Measurement and analysis of ME dispersion characteristics, including Maxwell-Wagner relaxation, and low-frequency ME effects. (iii) Investigations on resonant ME effect when the electric and magnetic subsystems show resonance behavior. Human resource development will involve personnel at all levels, from high school students to research associates. The ME materials are potential candidates for magnetoelectric memory devices, magnetic field sensors, electrically controlled magnetic devices, and magnetically controlled piezoelectric devices.