镝铒掺杂BaTiO3陶瓷的制备与介电性能

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1、哈尔滨工业大学工学硕士学位论文摘要采用溶胶凝胶法制备了分别掺杂DyEr的BaTi伪陶瓷，掺杂摩尔分数分别为0.001,0.002,0.003,0.005,0.007的BaTi03陶瓷，并对其结构、导电性和介电性的变化进行了研究，XRD结果表明:DyEr掺杂BaTi03陶瓷的晶相，仍为四方相。通过DyEr对BaTiO3陶瓷的掺杂，使其导电性发生了明显的变化。当Dy的掺杂摩尔分数为0.005时，室温电阻率从纯BaTiO3的2.6X10"Q。。下降为4.19X1少0·m,然后随着掺杂浓度的增加有所上升，呈现U型变化曲线。当Er的掺杂摩尔分数为0.007时，室温电阻率为1.85X1

2、口。。。m>DyEr掺杂BaTi伪陶瓷的交流电导随着温度的升高而增大，在Curie点附近达到最高，而后随着温度的升高反而下降，里现PTC效应。DyEr掺杂使BaTi03陶瓷的介电性也发生了明显的变化。Dy掺杂使BaTiO3陶瓷介电温谱呈现明显的PTC效应，居里温度降低为127.30C6Er掺杂使BaTiO3陶瓷的介电常数升高，居里温度升高为130.91C.Er掺杂BaTiO3陶瓷的频率特性优于Dy掺杂BaTi03陶瓷。对DyEr掺杂BaTi03陶瓷的导电性和介电性的变化机理进行了初步分析，根据容差因子计算初步确定Dy掺杂是同时取代钡离子和钦离子，Er掺杂主要以取代钦离子为主

3、。关键词稀土;钦酸钡陶瓷:导电性:介电性哈尔滨工业大学工学硕士学位论文AbstractBaTi03ceramicsdopedwithvariousqualitiesofDyandErwerepreparedrespectively(theadulterateconcentrationsare0.001,0.002,0.003,0.005,0.007mo1)throughaSol-Gelmethodandtheirelectricalpropertiesanddielectricpropertieswerestudied.ItisfoundthatthephaseofBaTi

4、03ceramicdopedwithDyandErisstilltetragonalphase.TheadulterationofDyandErmaketheelectricalpropertiesalterevidently.WhentheadditionofDyis0.005mol,theresistivitydecreasetothesmallest,whichchangesfrom2.6X1012。·into4A9X10'。·m.WhentheadditionofEris0.007mol,theresistivitydecreaseto1.85X10'00·m.Th

5、econductanceofthemodifiedBaTi03ceramicsdopedwithDyandEralterwiththechangeoftemperatureandexhibitanobviousPTCeffectThedielectricpropertyofBaTiO3ceramicschangedistinctlyafterBaTi03ceramicsdopedwithDyandET.ThedopingofDygiverisetothedielectrictemperaturefigureshowanevidentlyPTCefectandtheCurie

6、temperaturedecreaseto127.3'CeThedielectricconstantofBaTiO3ceramicsalsopresentPTCefectunderdiferenttemperatureaftertheadulterationofErandtheCurietemperatureis130.9'CThefrequencyofBaTi03ceramicsdopedwithErisgoodthanthatofBaTiO3ceramicsdopedwithDy.Thechangingmechanismofelectricpropertyanddiel

7、ectrcpropertyofmodifiedBaTi03ceramicsdopedwithDy,Erisdiscussedinitially.ItisdeterminedtheDyionreplacetheBaionandtheTiionintheBaTi03ceramicatthesametime,onthecontrarytheaimofreplacingofErionistheTiionintheBaTi03ceramic.Keywordsrareearth;BaTi03ceramics;electricp