QQ客服 官方微博 反馈留言

题名	掺杂Mn-Co-O系单片式NTC热敏电阻的研究
作者	贾素兰
学位类别	硕士
答辩日期	2011-05-31
授予单位	中国科学院研究生院
授予地点	北京
导师	陈朝阳
关键词	NTC热敏电阻 单层片式 低阻高B 多元醇法
学位专业	材料物理与化学
中文摘要	负温度系数(Negative Temperature Coefficient, NTC)陶瓷材料在温度测量、温度控制和温度补偿等方面得到广泛应用。目前片式化技术是NTC热敏电阻领域的研究热点，其中获得低阻高B型单层片式元件比较困难。 论文选择Mn-Co-O系氧化物为研究对象；以制备单层片式低阻高B热敏电阻为研究目标；以粉体材料合成工艺和掺杂改性为主要技术途径，开展了一系列的研究工作。研究了金属醇盐法制备纳米颗粒的反应机理；揭示了多重掺杂对Mn-Co-O基半导体陶瓷烧结特性、显微结构以及电性能的影响；最终将Mn-Co-Zn-Cu-Al-O系半导体氧化物烧结成瓷，且保持良好的低阻高B特性。具体研究主要包括以下三方面的内容： (1) 探索了多元醇法合成Mn-Co-Zn-Cu-Al-O纳米粉体的工艺。制备出了纳米颗粒大小在96～160nm范围内的前躯体粉末，研究发现：该粉末有较高的烧结活性以及均匀的化学组成，经1100℃烧结后形成致密度很好的样品，比传统固相法合成粉体的烧结温度降了大约100℃。 (2) 以制备低阻高B型NTC热敏电阻为目的，采用传统固相法工艺多重掺杂制备Mn-Co-O基半导体陶瓷，研究了多种掺杂剂(ZnO、CuO、Al2O3)对Mn-Co-O基半导体陶瓷烧结特性、显微结构以及电性能的影响。结果表明：掺入ZnO、Al2O3可以提高材料的电阻和B值，同时也提高了材料的稳定性；掺入CuO时电阻和B值都减小。 (3) 研究了NTC热敏电阻的烧结工艺和老化稳定性，探讨了不同烧结时间和烧结气氛对电学参数的影响，同时也研究了不同温度下样品的老化特性和γ射线照射下的稳定性。研究发现：降温速率加快和减小气氛中氧含量都有助于减小电阻率；掺杂Zn、Al可以提高电阻的老化稳定性；多重掺杂的辐射稳定性优于Mn-Co-O二元体系。
英文摘要	Negative Temperature Coefficient (NTC) ceramic are used in various industrial and domestic applications, such as elements for the suppression of in-rush current, the temperature measurement and control, and the compensation of other circuit elements. Recently the technique of layer components is hotspot of NTC thermistors，but it is difficult to make the low electrical resistivity and high B constant Single Layer Chip. The Mn-Co-O based ceramics were used as the research materials. The aim of our work is to prepare NTC ceramics with relatively low electrical resistivity and high B constant. Synthesis of high active nano-powders and doping were used as the main techniques. Series of research work have been carried out. The reactive mechanism about nanoparticles is prepared by polyol method. The effects of various additives on the microstructure, sintering characters and electrical properties of Mn-Co-O based ceramics were shown in the paper. Eventually series of Mn-Co-Zn-Cu-Al-O were sintered into high compact ceramics, while they kept excellent electrical properties of the relatively low electrical resistivity and high B constant.The main content of the dissertation are explained as follows: (1) The technique about sythesis of nano-power via polyol methods has been explored. The powders with average gain size between 96 and 160nm were prepared, which have a higher sintering activity and chemical composition of uniform. The powders were sintered at 1100℃ to form compact ceramics with relative high densities. Meanwhile the sintering temperature of samples prepared via traditional technique has been declined about 100℃. (2) In order to prepare the samples with the low electrical resistivity and high B, the Mn-Co-O based ceramics were prepared by traditional multi-doped solid state technology. It can be concluded that the added oxides of ZnO、Al2O3 lead to an increase in electrical resistivity and the B constant and the stability of the samples was improved, but the phase of CuO causes an decrease in those parameters . (3) NTCR sintering process and aging stability were studied. The effects of different sintering time and sintering atmosphere on the electrical parameters were investigated as well as aging characteristics at different temperature and the stability of γ-ray irradiation . It was shown that the high cooling rate and the low oxygen content will help to reduce the electrical resistivity; the aging stability can be improved by doping with Zn and Al; the samples with various additives are more stable than Mn-Co-O system, when irradiated.
内容类型	学位论文
源URL	[http://ir.xjipc.cas.cn/handle/365002/4431]
专题	新疆理化技术研究所_材料物理与化学研究室
作者单位	中国科学院新疆理化技术研究所
推荐引用方式 GB/T 7714	贾素兰. 掺杂Mn-Co-O系单片式NTC热敏电阻的研究[D]. 北京. 中国科学院研究生院. 2011.

个性服务

查看访问统计

相关权益政策

暂无数据

收藏/分享

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。