摘要KNN(K0.5Na0.5O3)是由铁电体铌酸钾 (KNbO3, KN)与反铁电体(正交)铌酸钠(NaNbO3, NN)组成的二元固溶体,具有优良的压电性能和机械性能,是目前备受关注的热门无铅压电材料之一。本论文分别采用水热法和固相法,经过工艺优化,制备了一系列KNbO3、NaNbO3和KNN粉体,并对其结构、形貌等开展了一系列分析。研究结果表明,在水热实验中,经过230℃、24小时的水热反应过程即可得到纯相的KNbO3和NaNbO3 ,在相同的实验条件下,并没有得到纯相的KNN粉体,存在KNbO3、NaNbO3、Nb2O5杂质。需要通过800℃、5小时热处理之后,可以得到完全纯相的KNN。在此基础上,利用相同的制备工艺,得到了纯相的Sm3+掺杂KNN粉体。由于反应活性较低,在固相反应过程中,经过800℃和900℃两次煅烧,仍然存在Nb2O5杂质,因此反应温度需要进一步提高。Sm3+掺杂KNN粉体的发光特性研究,发红色-黄色的光,同时,随着Sm3+浓度的升高发光强度降低,这是由于浓度淬灭效应造成。20185
毕业论文关键词: 铌酸钾钠;掺杂Sm3+改性;水热法;固相法
Abstract
KNN (K0.5Na0.5O3) is composed of ferroelectric potassium niobate (KNbO3, KN) and the electric iron body (orthogonal) sodium niobate (NaNbO3, NN) binary solid solution, with excellent piezoelectric properties and mechanical properties, is currently the focus of one of the hottest lead-free piezoelectric materials. This paper respectively by hydrothermal method and solid phase method, the optimized process, the preparation of a series of KNbO3, NaNbO3 and KNN powder, and the structure, morphology and so on has carried out a series of analysis. The results show that the experiment, the water is hot after 230 ℃, 24 hours of water thermal process can get pure phase KNbO3 and NaNbO3, under the same experimental conditions, didn't get the KNN powder, pure phase KNbO3, NaNbO3, Nb2O5. Needing 800 ℃ 5 hours after heat treatment, can get completely pure phase KNN. On this basis, using the same preparation technology, the pure phase of Sm3+ doped KNN powder. Due to the low reactivity, in the process of solid phase reaction, through 80℃ and 900℃ of two calcination. There were still some Nb2O5 impurities, so the reaction temperature need further improved. Sm3+doped luminescence properties of KNN powder, red-yellow light to be, at the same time, with the increase of concentration of Sm3 + strength is reduced, this is caused by the concentration quenching effect.
Key Words: KNN; Sm3+ doping modification; hydrothermal synthesis; solid phase synthesis
目录
1 绪论 1
1.1 KNN材料简述 1
1.1.1KNN晶体结构 1
1.2KNN晶体的性能 2
1.2.1介电特性 2
1.2.2压电与铁电特性 2
1.3KNN晶体的应用 3
1.4KNN陶瓷的制备方法 4
1.4.1聚合物前驱体法[7] 4
1.4.2固相反应法[8] 4
1.4.3熔盐法[9] 5
1.5选题的目的和意义 5
1.6研究内容和目标 6
2 实验部分 7
2.1 原料及试剂 7
2.2 实验设备和仪器 7
2.2.1 水热法基本介绍[13] 8
2.2.2 水热法合成KNbO3 9
2.2.3 水热法合成NaNbO3 10
2.2.4 水热法制备铌酸钾钠(KNN)粉体 11
2.2.5 水热法制备掺杂Sm的铌酸钾钠粉体 12
2.2.6 固相法制备铌酸钾钠粉体 12
3结果与讨论 13
3.1 水热法合成KNBO3、NANBO3 13
3.2 水热法合成铌酸钾钠粉体 14
3.3 固相法合成铌酸钾钠粉体 16 稀土掺杂KNN铁电材料的制备与性能研究:http://www.youerw.com/cailiao/lunwen_11861.html