Sol-Gel法制备NiCuZn铁氧体薄膜性能研究

发布时间：2018-04-20 12:15

  本文选题：铁氧体薄膜 + Sol-gel　； 参考：《兰州大学》2011年硕士论文

【摘要】：半导体集成技术的快速发展,要求电子元器件小型化和高频化,因而薄膜型材料近年来引起了人们广泛的关注。NiZn铁氧体具有高的电阻率和共振频率,适用于各种变压器,电感器等,在通讯、计算机、抗电磁干扰、电子等领域广泛应用。在NiZn铁氧体中掺杂适量的Cu,可以对NiZn铁氧体的适用频段进行一定的调节和改善,NiCuZn铁氧体已经成为NiZn系铁氧体中十分重要的分支。因而制备出性能优良的NiCuZn铁氧体薄膜具有重要意义。 本文通过sol-gel旋转涂层方法制备了NiCuZn铁氧体薄膜,研究了溶胶性质、退火温度、保温时间、旋涂过程等工艺条件对NiCuZn铁氧体薄膜晶体结构、微观形貌以及磁性能方面的影响,同时还研究了成份变化、磁场真空快速热处理对铁氧体薄膜性能的影响,从中摸索提高铁氧体薄膜饱和磁度Ms和降低矫顽力Hc的方法。通过X射线衍线仪、振动样品磁强计、扫描电镜以及原子力学显微镜等方法对NiCuZn铁氧体薄膜进行表征,得到以下结论： (1)通过对干凝胶的TG-DTA曲线分析,确定了制备过程中去除NiCuZn铁氧体薄膜的水份和有机物的温度分别为120℃和300℃。当匀胶机转速4000rpm,旋涂时间30s,旋涂三层时制备的NiCuZn铁氧体薄膜均匀,性能较好,薄膜的厚度约为240nm。 (2)对溶胶性质的研究发现,溶度为0.2mol/L、陈化24小时、聚乙二醇加入量为25g/L的溶胶制备的NiCuZn铁氧体薄膜性能最佳。 (3)将NiCuZn铁氧体薄膜样品进行退火处理。升温速率为2℃/min,保温2小时,500℃样薄膜样品为单相的尖晶石结构,高于600℃,由于Zn元素的挥发,出现a-Fe2O3的杂相。薄膜的饱和磁化强度Ms和矫顽力Hc都随温度增加先增大后减小,800℃退火的铁氧体薄膜具有最大的饱和磁化强度Ms=355 emu/cc,接近对应铁氧体块体的饱和磁化强度,对应的矫顽力Hc=150 Oe。可见,sol-gel方法可有效降低NiCuZn铁氧体的烧结温度,实现低温共烧结。 (4)改变Ni、Cu元素比例制备了不同成份的Ni0.8-xCuxZn0.2Fe2O4薄膜,经600℃保温2小时退火处理后,其饱和磁化强度Ms随x先增大后减小,组份为Ni0.4Cu0.4Zn0.2Fe2O4的薄膜具有最大饱和磁化强度Ms,达到284 emu/cc。铁氧体薄膜的矫顽力呈随x呈单调递减的趋势,Ni0.2Cu0.6Zn0.2Fe2O4组份的铁氧体薄膜的矫顽力Hc低至15 Oe。通过对Cu掺杂量的变化,实现了对Ms和Hc的调节。 (5)对Ni0.4Cu0.4Zn0.2Fe2O4组份的铁氧体薄膜样品尝试进行了磁场真空快速热处理,发现热处理后的样品较管式炉退火样品性能变差,我们分析认为这是由于磁场热处理过程没有有效消除薄膜中存在的应力。
[Abstract]:With the rapid development of semiconductor integration technology, the miniaturization and high frequency of electronic components are required. In recent years, thin film materials have attracted wide attention. NiZn ferrite has high resistivity and resonance frequency, so it is suitable for various transformers. Inductor is widely used in communication, computer, anti-electromagnetic interference, electronics and so on. Doping appropriate amount of Cu in NiZn ferrite can adjust the suitable frequency band of NiZn ferrite and improve the content of NiCuZn ferrite. It has become an important branch of NiZn ferrite. Therefore, it is of great significance to prepare NiCuZn ferrite thin films with excellent properties. In this paper, NiCuZn ferrite thin films were prepared by sol-gel rotating coating method. The effects of sol properties, annealing temperature, holding time and spin-coating process on the crystal structure, microstructure and magnetic properties of NiCuZn ferrite films were investigated. At the same time, the effects of composition change and magnetic field vacuum rapid heat treatment on the properties of ferrite thin films were studied. The methods to improve the saturation magnetization of ferrite films and to reduce the coercivity HC were explored. The NiCuZn ferrite films were characterized by X-ray diffractometer, vibrating sample magnetometer, scanning electron microscope and atomic mechanics microscope. 1) by analyzing the TG-DTA curves of xerogels, the temperature of water and organic matter removed from NiCuZn ferrite films was determined to be 120 鈩，

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