【作者】 金建华；

【导师】 陈实；

【作者基本信息】 华中科技大学 ， 集成电路工程（专业学位）， 2024， 硕士

【摘要】 对于以非晶磁致伸缩材料为磁性层的层状磁电复合材料,磁性层晶化作为一种增强磁电耦合进而提升整体性能的有效途径被广泛采用。然而晶化对磁电耦合的具体影响尚不清晰,晶化度的合适范围也未界定。针对这些问题,本文系统地探索了磁性层晶化对磁电复合材料性能的调控作用,确定了优化的晶化度范围,深入研究了高性能磁电复合材料的设计制备,主要研究工作包括:首先,选取了Metglas/PMN-PT作为磁电复合材料的磁致伸缩/压电材料,设计了L-T型层状磁电复合材料,仿真研究了磁性层结构参数对磁电耦合的影响。基于仿真结果,优化了磁性层的结构设计。随后,研究了晶化对Metglas性能的影响。结果表明:随着晶化度的升高,Metglas的磁机耦合性能先升后降,而软磁性能最初基本维持不变,随后急剧劣化。相较非晶Metglas,晶化度在4.55%～6.43%之间时,Metglas的磁机耦合系数和优值分别提升了62.9%～93.5%和62.4%～69.2%,且磁导率和矫顽场维持在较好水平。之后,研究了磁性层晶化对磁电耦合的影响。结果表明:磁电耦合性能随磁性层晶化度的升高先升后降。相较基于非晶Metglas的磁电复合材料,磁性层晶化度在4.55%～6.43%之间时,磁电复合材料的磁电耦合系数在谐振频率处和非谐振频率处分别提升237.6%～298.7%和173.4%～242.0%,最佳偏置磁场维持在较低水平。最后,研究了磁性层晶化对磁电复合材料应用性能的调控作用。结果表明:合适程度的晶化可以有效提升磁电复合材料的各项应用性能,而大量晶化会导致性能的劣化。得益于结构的设计优化,及磁性层最佳晶化度(4.55%)引起的磁电耦合性能的大幅提升,制备的磁电复合材料的探测极限在谐振频率处和1 k Hz处分别达2.0 p T和3.3 n T,1 m处的辐射强度达3.36 n T,输出功率密度达40.4 m W/cm~3·Oe~2,平均充电功率达67.8μW。本研究为进一步提升磁电复合材料的性能提供了重要的参考。更多还原

【Abstract】 For laminated magnetoelectric composites with amorphous magnetostrictive materials as the magnetic layers,the crystallization of the magnetic layers has been widely adopted as an effective approach to enhance the magnetoelectric coupling and thus the overall performance.However,the specific effect of crystallization on magnetoelectric coupling remains unclear,and the appropriate range of crystallinity has not been defined.Addressing these issues,this dissertation systematically explored the modulation effect of the crystallization of the magnetic layers on the performance of laminated magnetoelectric composites,determined the optimized range of crystallinity,thoroughly investigated the design and preparation of high-performance magnetoelectric composites.The main research work included:Firstly,Metglas/PMN-PT were selected as the magnetostrictive/piezoelectric materials of the magnetoelectric composites.Laminated magnetoelectric composites based on L-T structure were designed,and the effect of the structural parameters of the magnetic layers on magnetoelectric coupling was studied through simulation.Based on the simulation results,the structural design of the magnetic layers was optimized.Subsequently,the effect of crystallization on the properties of Metglas was studied.The results indicated that,as the crystallinity increased,the magnetomechanical properties of Metglas initially rose and then declined,while the soft magnetic properties remained relatively unchanged at first,followed by a rapid deterioration.Compared with amorphous Metglas,when the crystallinity was between 4.55%and 6.43%,the magnetomechanical coupling factor and figure of merit of Metglas increased by 62.9%to 93.5%and 62.4%to69.2%,respectively,while the permeability and coercivity maintained at good levels.Afterwards,the effect of crystallization of the magnetic layers on the magnetoelectric coupling performance was investigated.The results indicated that,as the crystallinity increased,the magnetoelectric coupling performance initially rose and then declined.Compared with the magnetoelectric composites based on amorphous Metglas,when the crystallinity of the magnetic layers was between 4.55%and 6.43%,the magnetoelectric coupling coefficient of the magnetoelectric composites increased by 237.6%to 298.7%at resonance frequency,and 173.4%to 242.0%at off-resonance frequency,while the optimum bias magnetic field maintained at a low level.Finally,the modulation effect of crystallization of the magnetic layers on the application performance of the magnetoelectric composites was investigated.The results indicated that,moderate crystallization could effectively enhance the application performance of the magnetoelectric composites,while excessive crystallization could lead to performance deterioration.Benefiting from the optimized structural design,and the substantial improvement in magnetoelectric coupling performance induced by the optimal crystallinity(4.55%)of the magnetic layers,the limit of detection of the prepared magnetoelectric composites reached 2.0 p T at resonance frequency and 3.3 n T at 1 k Hz.The radiation intensity at a distance of 1 m reached 3.36 n T.The output power density reached 40.4 m W/cm~3·Oe~2,and the average charging power reached 67.8μW.This research provides valuable references for further enhancing the performance of magnetoelectric composites.更多还原