镍锰系尖晶石型负温度系数热敏电阻薄膜的制备及其性能研究
发布时间：2018-11-12 07:53
【摘要】：常用的负温度系数(NTC)热敏电阻是由具有尖晶石结构的过渡族金属氧化物固溶体组成的。NTC热敏材料主要应用于温度测量、温度控制和抑制浪涌电流等方面。作为一种电子材料,NTC热敏材料的小型化和薄膜化是发展的必然趋势。常用的薄膜制备工艺主要有丝网印刷法、脉冲激光法、蒸发法、磁控溅射法、溶胶凝胶法和水热沉积法。其中,传统的薄膜制备方法普遍存在工艺复杂、制备效率低和后期处理困难的不足,而水热法制备薄膜是在液相中一次完成,无需退火或晶化处理,避免了薄膜在后期处理过程中可能导致的晶粒粗化、薄膜卷曲开裂以及薄膜与基体反应而引起薄膜性能的不稳定等问题。本研究采用水热沉积法制备镍锰系尖晶石结构热敏薄膜材料,并在薄膜中掺杂A1和Zn离子,采用XRD、SEM、XPS和阻温测试等方法研究了材料的组织结构和性能,实现了改善材料电学性能,获得最优材料配方的目的。本论文的主要研究内容如下:通过水热沉积法制备尖晶石NTC热敏薄膜材料。首先在氧化铝陶瓷基片上水热沉积制备NiMn1.8A10.2O4热敏薄膜。研究不同反应时间(2 h、5 h、10 h和15 h)对薄膜的微观结构和电学性能的影响。结果表明,反应温度为230℃,反应时间2 h条件下即可沉积出致密性良好的热敏薄膜。薄膜晶粒尺寸随着反应时间的增加逐渐增大,反应在2h时,晶粒平均直径在2.5μm,随着反应时间增加到15 h,平均晶粒尺寸达到了 5.4μm。不同反应时间沉积的薄膜均具有良好的NTC特性,随反应时间增加,材料常数和激活能随反应时间的增大而增大。在反应时间为15 h时,其材料常数达到了 4645 k。本研究表明水热法是一种低温下制备良好NTC热敏特性薄膜材料的新方法,为用水热法制备NTC热敏薄膜提供技术支撑。通过水热沉积法制备NiMn1.8-xA10.2ZnxO4(0 ≤ x ≤ 0.2)系NTC热敏薄膜材料。首先在优化的水热沉积工艺参数(230℃,15 h)下制备掺杂Zn的镍锰铝尖晶石结构NTC热敏薄膜,主要研究Zn含量对薄膜的微观结构和电学性能的影响。通过SEM可以观察到掺杂Zn的薄膜的典型微观结构,下层是与基底紧密结合的纳米片状结构,上层是颗粒状结构。随着Zn含量的增加,颗粒尺寸明显增大。通过XPS分析发现:随着Zn含量的增加,Mn总含量的减少,膜中Mn2+的含量减少,而Mn+3/Mn+4含量增加。通过电学性能分析,表明所沉积的薄膜具有良好的负温度系数(NTC)热敏特性,其室温电阻随着Zn含量的增加而增大,材料常数在4000～4200 K之间。掺杂Zn的薄膜在150℃老化300 h后,即可得到稳定的NTC热敏薄膜,最大老化率为22.2%,老化研究表明通过掺杂Zn能得到稳定性较高的NTC热敏薄膜材料。
[Abstract]:The commonly used negative temperature coefficient (NTC) thermistor is composed of transition metal oxide solid solution with spinel structure. NTC thermistor is mainly used in temperature measurement, temperature control and suppression of surge current. As an electronic material, the miniaturization and thinning of NTC thermal sensitive materials is an inevitable trend. The main techniques of thin film preparation are screen printing, pulsed laser, evaporation, magnetron sputtering, sol-gel and hydrothermal deposition. Among them, the traditional preparation methods of thin films have many disadvantages, such as complex process, low preparation efficiency and difficulty in post-treatment. However, hydrothermal preparation of thin films is completed in the liquid phase, without the need of annealing or crystallization. The problems of coarsening, crimp cracking and the instability of the film properties caused by the reaction between the film and the substrate are avoided. In this paper, Ni-Mn spinel structure thermistor thin films were prepared by hydrothermal deposition. The microstructure and properties of the films were studied by doping Al and Zn ions, XRD,SEM,XPS and temperature resistance test. The purpose of improving the electrical properties of materials and obtaining the optimal material formula is achieved. The main contents of this thesis are as follows: spinel NTC thin films were prepared by hydrothermal deposition. Firstly, NiMn1.8A10.2O4 thin films were prepared by hydrothermal deposition on alumina substrates. The effects of different reaction time (2 h, 5 h, 10 h and 15 h) on the microstructure and electrical properties of the films were studied. The results show that the thermosensitive films with good densification can be deposited at 230 鈩，
本文编号：2326525
[Abstract]:The commonly used negative temperature coefficient (NTC) thermistor is composed of transition metal oxide solid solution with spinel structure. NTC thermistor is mainly used in temperature measurement, temperature control and suppression of surge current. As an electronic material, the miniaturization and thinning of NTC thermal sensitive materials is an inevitable trend. The main techniques of thin film preparation are screen printing, pulsed laser, evaporation, magnetron sputtering, sol-gel and hydrothermal deposition. Among them, the traditional preparation methods of thin films have many disadvantages, such as complex process, low preparation efficiency and difficulty in post-treatment. However, hydrothermal preparation of thin films is completed in the liquid phase, without the need of annealing or crystallization. The problems of coarsening, crimp cracking and the instability of the film properties caused by the reaction between the film and the substrate are avoided. In this paper, Ni-Mn spinel structure thermistor thin films were prepared by hydrothermal deposition. The microstructure and properties of the films were studied by doping Al and Zn ions, XRD,SEM,XPS and temperature resistance test. The purpose of improving the electrical properties of materials and obtaining the optimal material formula is achieved. The main contents of this thesis are as follows: spinel NTC thin films were prepared by hydrothermal deposition. Firstly, NiMn1.8A10.2O4 thin films were prepared by hydrothermal deposition on alumina substrates. The effects of different reaction time (2 h, 5 h, 10 h and 15 h) on the microstructure and electrical properties of the films were studied. The results show that the thermosensitive films with good densification can be deposited at 230 鈩，
本文编号：2326525
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