The influence of local distortion on the electrical properties of the (1-x)(K0.5Na0.5)NbO3-x(Ba0.8C0.2)TiO3 system
The influence of local distortion on the electrical properties of the (1-x)(K0.5Na0.5)NbO3-x(Ba0.8C0.2)TiO3 system
复制标题
局部畸变对(1-x)(K0.5Na0.5)NbO3-x(Ba0.8C0.2)TiO3体系电学性能的影响
DOI：
10.1016/j.ceramint.2016.11.207
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发表时间：
2017
影响因子：
5.2
通讯作者：
S. Suasmoro
中科院分区：
文献类型：
--
作者：
U. Nuraini;D. Agustianawati;E. Yahya;Y. Cahyono;P. Kidkhunthod;S. Suasmoro
本工作采用固相反应和共沉淀草酸盐法相结合的方法，成功地合成了(1-x)(K0.5Na0.5)NbO3-x(Ba0.8Ca0.2)TiO3和所谓的(1-x)KNN-xBCT。通过X射线衍射谱分析进行了物相鉴定和晶体结构测定。用Nb L3边的XANES、TiK边的XANES和TiK边的EXAFS研究了掺杂引起的局域变形。研究了介电性能和电导率的电学特性，以解释局部失真的变化。室温下的X射线衍射谱分析表明，当x=0时，x=0.1和x=0.2为四方结构。此外，用ARTEMIS进行EXAFS分析，揭示了氧的八面体扭曲和TiNb‘与其周围的距离。不同温度下的电导率测量表明，在室温下，所有样品都表现为正载流子，随着温度的升高，载流子变为负电荷。载流子转变的温度随BCT含量的增加而增加：KNN为150℃，0.9KNN-0.1BCT为180℃，0.8KNN-0.2BCT为220℃。介电性能的表征表明，KNN的居里温度为220℃和420℃，而KNN-BCT的峰向低温移动并变宽，这是典型的弛豫特性，被认为与ABO3结构中B位周围氧八面体排列的扭曲有关。
In this work, the composition of (1-x)(K 0.5 Na 0.5) NbO 3-x (Ba 0.8 Ca 0.2) TiO 3 and the so-called (1-x) KNN-xBCT were successfully synthesised using a combination of solid-state reaction and co-precipitation oxalate methods. Phase identification and crystal structure determination were carried out by means of XRD pattern analysis. Local distortion due to the dopant was studied by XANES at the Nb L3-edge, XANES at the Ti K-edge, and EXAFS at the Ti K-edge. Electrical characterisation of dielectric properties and conductivity were investigated to elucidate the changes in local distortion. XRD analysis at room temperature concluded that while x= 0 has an orthorhombic structure, x= 0.1 and x= 0.2 have as tetragonal structure. Furthermore, EXAFS analysis using Artemis revealed the oxygen octahedral distortion and distance of Ti Nb′ to its surroundings. Conductivity measurements at various temperatures showed that at room temperature, all samples behave as positive charge carriers, and when the temperature is increased, the charge carriers become negative. The temperatures at which charge carrier alteration increases with increasing BCT content are: 150° C for KNN, 180° C for 0.9 KNN-0.1 BCT and 220° C for 0.8 KNN-0.2 BCT. The characterisation of dielectric properties exhibited two Curie temperatures at 220° C and 420° C for KNN, while for KNN-BCT, the peaks shift to lower temperature and become broader, which is a typical relaxor characteristic and was thought to be related to the distortion of oxygen octahedral arrangement surrounding the B sites in the ABO 3 structure.
影响因子：
2.5
作者：
Ravel, B;Newville, M
通讯作者：
Newville, M