【作者】 刘俨；

【导师】 郝永德；

【作者基本信息】 华中科技大学 ， 微电子学与固体电子学， 2009， 硕士

【摘要】 近年来,低电阻BaTiO₃PTCR陶瓷材料在汽车电路过流过载保护、片式元件等方面得到了广泛的应用, PTCR材料电阻率的降低能够扩展高性能PTCR材料的应用范围,低电阻BaTiO₃PTCR陶瓷材料仍然是值得研究的。在综述低电阻率BaTiO₃PTCR陶瓷材料的制备和理论研究现状的基础上,提出了研究中存在的问题。通过实验,对低电阻率BaTiO₃PTCR材料的制备进行研究;研究烧结与低电阻率PTCR陶瓷材料性能的关系,同时研究烧结助熔剂Al2O3在BaTiO₃PTCR陶瓷材料中的作用。主要内容包括低电阻率BaTiO₃PTCR材料配方的设计,工艺的设计以及制备样品的测试与分析。在低电阻率BaTiO₃PTCR材料配方的设计中,阐述了BaTiO₃PTCR材料半导化的原理以及掺入的元素的作用,包括其对材料电阻率的影响,晶粒大小影响和PTC效应的影响等。对烧结后陶瓷的测试主要包括电阻率,电阻温度特性曲线,样品的表面形貌等,并对测试结果进行了分析,得出施主掺杂量、受主掺杂量以及液相掺杂剂的掺入量与材料电阻率的关系。文中根据得到的关系做出了曲线图,并作为设计配方的依据。在工艺方面,通过调节烧结温度,得出烧结温度对低电阻率BaTiO₃PTCR材料的影响,同时找到一个合适的烧结温度。最后,总结了以前所作的工作以及本项目的进展情况,同时对本项目还有待进一步解决的问题以及今后还需要做的工作做了相关展望。更多还原

【Abstract】 Recent years, BaTiO₃PTCR ceramics with low resistivity is widely used in over-current overload protection circuit,chip components and spaceflights.Reducing the resistivity of PTCR material is important because it can expand the scope of application of PTCR material,the sudy of BaTiO₃PTCR ceramics with low resistivity is important.In this paper,the existing questions on the studying of BaTiO₃PTCR ceramics with low resistivity were proposed,according to the reviewing of the conditions of preparation and the development of theory of it .Through a large amount of experiments,we studied the methods of preparation of low resistivity BaTiO₃PTCR ceramics.This article mainly covers the the design of BaTiO₃PTCR ceramics with low resistivity, the design of preparation,the test of the material and the analysis of the test results. In the design of BaTiO₃PTCR material with low-resistivity, this paper expound the mechanism of BaTiO₃PTCR becaming semiconducting materials, as well as the role of the element doped into the material, including its influence on the material resistivity, grain size and PTC effect.After sintering, the resistivity of the material ,the relation between resistance and temperature and the surface morphology of samples are tested .After analysing the testing results ,we find the relationgship between the resistivity of the material and the donor-doped ,the co-donor-doped and the sintering aids doped into the material .Based on the relationship,we get a curve used for designing the material .In the producing process,through regulation of sintering temperature ,we study the influence of the sintering temperature and find a fitting sintering temperatureFinally, by generalizing the work that before, the further question which also will wait for to solve has been taken out to analyze.更多还原