Study of bulk and grain-boundary conductivity of Ln2+xHf2−xO7−δ (Ln = Sm-Gd; x = 0, 0.096) pyrochlores
Study of bulk and grain-boundary conductivity of Ln2+xHf2−xO7−δ (Ln = Sm-Gd; x = 0, 0.096) pyrochlores
复制标题
Ln2+xHf2−xO7−δ (Ln = Sm-Gd; x = 0, 0.096) 烧绿石的体积和晶界电导率研究
DOI：
--
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
L. G. Shcherbakova
中科院分区：
文献类型：
--
作者：
A. Shlyakhtina;S. Savvin;A. Levchenko;A. Knotko;Petra Fedtke;A. Busch;T. Barfels;M. Wienecke;L. G. Shcherbakova
本文比较了新型固体电解质eu2.096 hf1.9040 o6.952和Gd2Hf2O7与钛酸盐和锆酸盐Ln2+xМ2−xO7−δ (Ln = Sm-Lu; M = Ti, Zr; x = 0−0.81)的电导率。阻抗谱数据表明，由机械活化氧化物合成的eu2.096 hf1.9040 o6.952和Gd2Hf2O7具有较高的离子电导率，与它们的锆酸盐类似物相当。测定了sm2.096 hf1.9040 o6.952 （Тsynth = 1600ºС）、eu2.096 hf1.9040 o6.952和Gd2Hf2O7 （Тsynth = 1670ºС）中电导率的体积和晶界成分。在1600ºC和1670ºC制备的无序焦绿石的体积电导率最高：sm2.096 hf1.9040 o6.952为1.5 × 10−4 S/cm, eu2.096 hf1.9040 o6.952为5 × 10−3 S/cm， Gd2Hf2O7在780ºС为3 × 10−3 S/cm。在Ln2+xМ2−xO7−δ (Ln = Eu, Gd; M = Zr, Hf; x ~ 0.286)固溶体和高温类荧光相Ln2+xМ2−xO7−δ (Ln = Eu, Gd; M = Zr, Hf; x = 0 ~ 0.286)的相界上，类荧光相的电导率低于无序焦绿石Ln2+xМ2−xO7−δ (Ln = Eu, Gd; M = Zr, Hf; x = 0 ~ 0.096)的相界电导率。
The electrical conductivity of new solid electrolytes Eu2.096Hf1.904O6.952 and Gd2Hf2O7 have been compared with those for different pyrochlores including titanates and zirconates Ln2+xМ2−xO7−δ (Ln = Sm-Lu; M = Ti, Zr; x = 0−0.81). Impedance spectroscopy data demonstrate that Eu2.096Hf1.904O6.952 and Gd2Hf2O7 synthesized from mechanically activated oxides have high ionic conductivity, comparable to that of their zirconate analogues. The bulk and grain-boundary components of conductivity in Sm2.096Hf1.904O6.952 (Тsynth = 1600ºС), Eu2.096Hf1.904O6.952 and Gd2Hf2O7 (Тsynth = 1670ºС) have been determined. The highest bulk conductivity is offered by the disordered pyrochlores prepared at 1600ºC and 1670ºC: ~1.5 × 10−4 S/cm for Sm2.096Hf1.904O6.952, 5 × 10−3 S/cm for Eu2.096Hf1.904O6.952 and 3 × 10−3 S/cm for Gd2Hf2O7 at 780ºС, respectively. The conductivity of the fluorite-like phases at the phase boundaries of the Ln2+xМ2−xO7−δ (Ln = Eu, Gd; M = Zr, Hf; x ~ 0.286) solid solutions, as well as that of the high-temperature fluorite-like phases Ln2+xМ2−xO7−δ (Ln = Eu, Gd; M = Zr, Hf; x = 0−0.286), is lower than the conductivity of the disordered pyrochlores Ln2+xМ2−xO7−δ (Ln = Eu, Gd; M = Zr, Hf; x = 0−0.096).