Effect of local A-site strain on dipole stability in A6GaNb9O30 (A = Ba, Sr, Ca) tetragonal tungsten bronze relaxor dielectrics.
Effect of local A-site strain on dipole stability in A6GaNb9O30 (A = Ba, Sr, Ca) tetragonal tungsten bronze relaxor dielectrics.
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DOI：
10.1039/c4dt03936j
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发表时间：
2015-06
影响因子：
4
通讯作者：
Andrew J. Miller;A. Rotaru;D. Arnold;F. Morrison
中科院分区：
文献类型：
--
作者：
Andrew J. Miller;A. Rotaru;D. Arnold;F. Morrison
本文研究了一系列等电子数A位取代的弛豫介电四钨青铜（Ba（6-x-y）Sr（x）Ca（y）GaNb（9）O（30））。通过常规衍射技术确定的长程（平均）晶体结构根据Vegard定律单调变化。然而，介电性质不显示类似的、简单的“平均尺寸”依赖性，而是显示对A-阳离子的统计尺寸方差（即尺寸失配）的依赖性。讨论了Vogel-Fulcher分析相对介电常数的困难和使用介电损耗数据拟合Jonscher经验通用介电弛豫模型的补充方法。
A series of isovalently A-site substituted relaxor dielectric tetragonal tungsten bronzes of general formula Ba(6-x-y)Sr(x)Ca(y)GaNb(9)O(30) were investigated. The long-range (average) crystal structure as determined by conventional diffraction techniques varies monotonically according to Vegard's law. The dielectric properties, however, do not display a similar, simple "average size" dependence and instead show a dependence on the statistical size variance, i.e. size mismatch, of the A-cation. The difficulties in Vogel-Fulcher analysis of relative permittivity and the complementary approach of using dielectric loss data fitted to Jonscher's empirical universal dielectric relaxation model is discussed.