KNN基无铅压电陶瓷的相界设计与电学性能研究
发布时间：2018-07-11 17:26
本文选题：KNN无铅压电陶瓷 + 相界构建 ； 参考：《西南民族大学》2017年硕士论文
【摘要】：碱金属铌酸盐(KNN)基无铅压电陶瓷因其良好的压电性能和较高的居里温度,是最有潜力取代铅基压电陶瓷的无铅压电陶瓷体系之一。为提高KNN陶瓷的电学性能,研究较为广泛的是降低正交-四方相变温度(TO-T),在室温附近构建正交-四方相界;或是提高三方-正交相变温度(TR-O),在室温区构建三方-正交相界。然而,这两种手段得到的KNN陶瓷体系的压电常数与铅基压电陶瓷相比仍存在很大的差距。近年来,研究者提出在KNN陶瓷中构建类似于Pb(Zr,Ti)O_3体系的三方-四方准同型相界(R-T相界)的新思路,将TO-T和TR-O同时调控至室温附近,成功的得到了一些高性能的KNN陶瓷体系。本论文以“新型相界构建”新思路为出发点,系统研究了(Bi,Sm)_(0.5)Na0.5ZrO_3和(Bi,Me)_(0.5)(Na,K)_(0.5)ZrO_3(简写为BSNZ和BMNKZ,其中Me3+=La3+、Nd3+、Sm3+)添加物对(K,Na)NbO_3(KNN)、(K,Na)(Nb,Sb)O_3(KNNS)和(K,Na)(Nb,Ta,Sb)O_3(KNNTS)的微观形貌、晶体结构、相界演变和宏观性能的影响。结果显示,添加BSNZ和BMNKZ能够在室温区构建出R-T/R-O-T相界,从而大大提高了体系的电学性能。本文研究结果如下:1.采用传统固相反应法制备了(1-x)K_(0.48)Na_(0.52)NbO_3-x(Bi_(0.46)Nd_(0.04))(Na_(0.82)K_(0.18))_(0.5)ZrO_3(简写为KNN-xBNNKZ)、(1-x)K_(0.48)Na_(0.52)NbO_3-x(Bi_(0.46)La_(0.04))(Na_(0.82)K_(0.18))_(0.5)ZrO_3(简写为KNN-xBLNKZ)、和(1-x)K_(0.48)Na_(0.52)NbO_3-x(Bi_(0.45)Sm_(0.05))(Na_(0.82)K_(0.18))_(0.5)ZrO_3(简写为KNN-xBSNKZ)三个陶瓷体系。研究发现,随着BMNKZ含量的增加,TO-T和TR-O同时被调控至室温附近。当室温区实现R-T或R-O-T共存态时体系压电性能大幅增强。三个压电陶瓷体系的最优性能如下:KNN-xBNNKZ(x=0.05),d33=308pC/N,kp = 43%,εr=1205,tanδ=3.8%,Pr=23.45 μC/cm2,TC=331 °C;KNN-xBLNKZ(x=0.05),d33=368 pC/N,kp = 44.7%,εr =1358,tanδ=3.5%,Pr=22.8 μC/cm2,Ec=12kV/cm,TC=323°C;KNN-xBSNKZ(x=0.05),d33=342 pC/N,kp = 46%,εr =1476,tanδ=4.3%,Pr=23.7 μC/cm2,Ec=12 kV/cm,TC=328°C。2.采用传统固相反应法制备了(1-x)K_(0.48)Na_(0.52)Nb0.96Sb0.04O_3-x(Bi_(0.45)Sm_(0.05))(Na_(0.82)K_(0.18))_(0.5)ZrO_3(简写为KNNS-x BSNKZ)陶瓷体系。研究发现,随着BSNKZ含量的增加,体系的TO-T下降较快,而TR-O上升相对缓慢,二者相互靠近最终在室温区实现R-T的共存,此时陶瓷的压电性能最优:KNNS-xBSNKZ(x=0.045),d33=480 pC/N,kp=48%,εr=2180,tanδ=3.6%,Pr=19.5μC/cm2,Ec=8.1 kV/cm,TC=258°C。3.采用传统的固相反应法制备了0.96K0.4Na0.6Nb0.97-xTa0.03SbxO_3-0.04(Bi_(0.45)Sm_(0.05))Na0.5ZrO_3(简写为KNNTSx-BSNZ)陶瓷体系。研究发现,随着Sb含量的增加,TO-T和TR-O很快被调控至室温附近。当Sb的含量从0.02变到0.07时,陶瓷在室温附近均为R-T共存,当x=0.045时陶瓷体系性能最优:KNNTSx-BSNZ(x=0.045),d33=510 pC/N,kp=44%,εr=2136,tanδ=4.1%,Pr=20.4μC/cm2,Ec=7.85 kV/cm,TC=238°C。
[Abstract]:Alkaline niobate (KNN) based lead-free piezoelectric ceramics is one of the most promising lead-free piezoelectric ceramics because of its good piezoelectric properties and high Curie temperature. In order to improve the electrical properties of KNN ceramics, it is widely studied to reduce the temperature of orthorhombic phase transition (TO-T), to construct the quadrature tetragonal phase boundary near room temperature, or to increase the temperature of the orthorhombic phase transition temperature (TR-O) to construct the rhombohedral interphase boundary at room temperature. However, the piezoelectric constants of KNN ceramics obtained by these two methods are still far from those of lead-based piezoelectric ceramics. In recent years, researchers have proposed a new idea of constructing a three-tetragonal quasi-homogeneous phase boundary (R-T phase boundary) similar to Pb (Zr-Ti) O _ 3 system in KNN ceramics. TO-T and TR-O are simultaneously controlled to near room temperature, and some high performance KNN ceramic systems have been successfully obtained. 鏈鏂囦互鈥滄柊鍨嬬浉鐣屾瀯寤衡，
本文编号：2116019
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