Structural and dielectric study of theNa0.5Bi0.5TiO3–PbTiO3and K0.5Bi0.5TiO3–PbTiO3systems
Structural and dielectric study of theNa0.5Bi0.5TiO3–PbTiO3and K0.5Bi0.5TiO3–PbTiO3systems
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DOI：
10.1039/a602148d
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发表时间：
1997
影响因子：
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通讯作者：
O. Elkechai;P. Marchet;P. Thomas;M. Manier;J. Mercurio
中科院分区：
文献类型：
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作者：
O. Elkechai;P. Marchet;P. Thomas;M. Manier;J. Mercurio
用X射线衍射、差示扫描量热和介电测量等方法研究了Na0.5Bi0.5TiO3-PbTiO 3和K0.5Bi0.5TiO3-PbTiO 3体系。菱形（Na 0.5 Bi 0.5 TiO 3 -丰富的一面）和四方（PbTiO 3 -丰富的一面）的固溶体的限制已被确定，以及它们的晶格参数作为组成和温度的函数的演变。陶瓷材料已经通过相应的氧化物和碳酸盐的固态反应（900-1000 ° C; 20小时）获得的粉末的自然烧结（1090-1220 °C; 0.5小时）来制备。这些材料的介电常数已在20至800 °C的温度下在宽频率范围内测量。结果表明，它们在室温下都是铁电体，并且根据组成的不同，表现出从铁电体到顺电态的扩散的，可能是二级相变，或者尖锐的，一级相变。
A study of the Na 0.5 Bi 0.5 TiO 3 –PbTiO 3 and K 0.5 Bi 0.5 TiO 3 -PbTiO 3 systems has been carried out using X-ray diffraction, differential scanning calorimetry and dielectric measurements. The limits of the rhombohedral (Na 0.5 Bi 0.5 TiO 3 -rich side) and tetragonal (PbTiO 3 -rich side) solid solutions have been determined, as well as the evolution of their lattice parameters as a function of composition and temperature. Ceramic materials have been prepared by natural sintering (1090–1220 °C; 0.5 h) of powders obtained by solid-state reaction (900–1000 °C; 20 h) of the corresponding oxides and carbonates. The dielectric permittivities of these materials have been measured in a wide frequency range for temperatures between 20 and 800 °C. The results showed that they all are ferroelectric at room temperature and exhibit either a diffuse, probably second-order phase transition, or a sharp, first-order-like phase transition from the ferroelectric to the paraelectric state, depending on the composition.