【作者】 夏新蕊；

【导师】 邓昭平；

【作者基本信息】 成都理工大学 ， 材料学， 2007， 硕士

【摘要】 PTC材料是一种温度敏感的铁电半导体材料，是近年来发展迅速的新型电子材料之一。PTC陶瓷材料因其独特的机-电-热物理性能，在电子信息、自动控制、生物技术、能源交通等领域得到了广泛应用，与陶瓷电容器和压电陶瓷并列成为铁电陶瓷的三大应用领域。但是，目前高居里温度PTC材料都是用含铅物质作为居里温度移动剂来制备的，而铅是对人体和环境有很大的危害。因此，需要研制一种新型环保无铅高居里温度PTC材料。本文采用固相合成法预先合成BNT，作为居里温度移动剂在二次合成时和其它物质一起加入，制备新型环保的无铅高居里温度PTC材料。借助X射线衍射仪（XRD）、扫描电子显微镜（SEM）、阻温特型测试仪（R-T）、伏安特性测试仪（V-A）等仪器对所制备的材料的微观组织及其制备的样品性能的进行了测试和表征。结果表明：在烧成温度850℃～950℃之间预先合成的BNT，可以作为制备无铅高居里温度PTC材料的高居里温度移动剂替代铅。如果BNT不预先合成而是以各自的化合物的形式加入，Bi和Na的化合物就会在制备的各个过程损失，而不能起到居里温度移动剂的效果。预先合成的BNT和主晶相BaTiO₃及其它添加剂进行二次合成，制备出无铅高居里温度PTC材料。添加剂为Ca，施主添加剂以Y₂O₃所制备的PTC材料在微观组织和电性能都较好。本实验采用预先合成的BNT，替代含铅物质作为居里温度移动剂制备出居里温度大于130℃的PTC材料，所制备的PTC元件室温电阻小于1kΩ，升阻比为10²；为电子材料领域研制新型环保的无铅PTC材料起到了一定的作用。更多还原

【Abstract】 PTC materials is a kind of temperature-sensitive ferroelectric semiconductor, which is one of new type electronic materials developed rapidly during the recent years. For particular mechanical-electronic-caloric physical property, PTC materials have been used broadly in the electronic information, autocontrol, biology technology, energy sources and traffic fields, is intituled paratacticly three applied areas of the ferroelectric ceramic with ceramic capacitor and piezoelectric ceramic. However, at present high-curie temperature PTC materials mostly used lead-substance to move the curie temperature. It is well known that lead is very harmful to person and environment. So it is necessary to develop a kind of new-type environmental lead-free high-curie temperature PTC materials.In this thesis, we firstly prepared BNT with solid composed method and prepared new-type environmental lead-free high-curie temperature PTC materials with the BNT and other additives. Also characterized the PTC materials’ microstructure and tested its samples’ property by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, Resistance-Temperature apparatus, Volt-Ampere testing apparatus and so on.Experiment results show that: the BNT which is sintered at the temperature from 850℃to 950℃can be used the moving-curie temperature substance instead of lead. If the BNT is not composed beforehand, the elements Bi and Na will be lost during the course and result in not moving the curie temperature. Through the second compose of BNT, main crystal BaTiO₃ and other additives, the lead-free high-curie temperature PTC materials can be prepared. The PTC materials’ microstructure and electrical property is better with additives Ca and donated additives Y₂O₃.The PTC materials that we prepare in this experiment is better. Its curie temperature go beyond 130℃, the sample’s resistance at the room temperature is less than 1kΩ, the ratio between the maximum resistance and the minimum resistance is 10². This PTC materials make some action on the electrical materials for researching new-type environmental lead-free PTC materials.更多还原