【作者】 林宏；

【导师】 袁望治；

【作者基本信息】 华东师范大学 ， 凝聚态物理， 2007， 硕士

【摘要】 基于薄膜材料易于集成化、微型化,在巨磁阻抗效应器件方面有着重大的应用前景,本文采用磁控溅射法制备了FeCuNbSiB/Si02/Cu/Si02/FeCuNbSiB/Si02型复合结构多层膜,利用XRD谱、表面磁光克尔效应(SMOKE)和磁导率频谱对由溅射功率和退火温度引起的材料磁性能的变化,以及对巨磁阻抗效应的影响进行了研究。1.当改变制备磁性层的溅射功率时,随着溅射功率的增加,多层膜样品的平面矫顽力逐渐减小,软磁性能提高,巨磁阻抗效应增大。当溅射功率为150W时,制备态样品出现最大的阻抗效应,横向阻抗效应为53%,纵向阻抗效应为44.3%;但溅射功率增加至200W后,由于溅射应力增大,样品出现了一定的垂直各向异性,巨磁阻抗效应明显减弱。2.退火温度对FeCuNbSiB多层膜的磁性能影响很大。当退火温度为400℃时,样品的极向克尔磁滞回线表现出较大矫顽力、高矩形比的垂直各向异性,导致样品的软磁性能减弱,巨磁阻抗效应显著下降。540℃退火处理后,样品纳米晶化,表现出优异的软磁性能,横向阻抗效应最高达到102.7%。3.利用复数磁导率和等效电路讨论了该多层膜的磁化过程,及其与GMI效应的关系。外加直流磁场抑制磁畴运动,在等效电路中与抵消的并联电路相关。样品磁化的特征弛豫频率在12MHz左右,与出现最大磁阻抗变化的频率接近。更多还原

【Abstract】 Due to the significant application perspective in the giant magneto-impedance （GMI） effect devices of film materials which are prone to integration and micromation, we have prepared FeCuNbSiB/SiO₂/Cu/SiO₂/FeCuNbSiB/SiO₂ multilayer films by magnetron sputtering method. By the methods of X-ray diffraction spectrums, surface magneto-optic Kerr effect and permeability spectrums, the changes of the samples’ magnetic properties and GMI effect upon different sputtering powers and annealing temperatures are studied.1. With the increase of the sputtering power of magnetic layers, the plane coercive force of the samples decreased, which enhanced the soft magnetic properties and GMI effect. The sample deposited by sputtering power of 150W had the maximal GMI effect, 53% and 44.3% in transverse and longitudinal MI effect respectively. However, when the sputtering power reached 200W, the increasing sputtering stress induced the perpendicular anisotropy in the sample, thus reduced remarkably GMI effect of the material.2. The magnetic properties of the samples were strongly affected by annealing temperatures. The polar Kerr hysteresis loops of the samples annealed at 400℃ exhibited perpendicular anisotropy of large coercive force and high rectangle ratio, which decreased soft magnetic properties and resulted in a dramatic fall of GMI effect. The samples annealed at 540℃ showed excellent soft magnetic properties by nano-crystallization, and the transverse magneto-impedance effect was high to 102.7%.3. Complex permeability and equivalent circuits were used to demonstrate the magnetization processes, which were relevant to GMI effect. The applied DC field was to produce a damping in domain wall movements, which was responsible for the minus parallel RL arm in equivalent circuits. The relaxation frequency of the sample was about 12MHz, near which the maximum GMI effect happened.更多还原