کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1296438 973781 2011 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Electrical properties of bulk and grain boundaries of scandia-stabilized zirconia co-doped with yttria and ceria
موضوعات مرتبط
مهندسی و علوم پایه شیمی الکتروشیمی
پیش نمایش صفحه اول مقاله
Electrical properties of bulk and grain boundaries of scandia-stabilized zirconia co-doped with yttria and ceria
چکیده انگلیسی

The electrical properties of bulk and grain boundaries of scandia-stabilized zirconia co-doped with yttria and ceria have been determined as a function of temperature (300 < T/°C < 700) and oxygen partial pressure [10− 24 ≤ p(O2)/bar ≤ 1, T = 700 °C] by application of impedance spectroscopy. The yttria and ceria contents of CexY0.2 − xSc0.6Zr3.2O8 − δ (0 ≤ x ≤ 0.2) have been varied systematically. Homogeneous samples have been prepared by means of a sol–gel (glycine-nitrate) combustion process. The ionic conductivity in air is almost independent of composition with typical values around 0.03–0.04 S cm− 1 for the bulk at 700 °C. A significant decrease of the ionic conductivities of bulk and grain boundaries is found for samples co-doped with ceria at low oxygen partial pressures [p(O2) < 10− 15 bar, T = 700 °C]. Activation energies for the ionic transport in oxidizing (air) and reducing (1%-H2/Ar) atmospheres have been extracted from Arrhenius-plots. The oxygen nonstoichiometry in 1%-H2/Ar has been investigated by employing thermogravimetry. The decrease of the ionic conductivity under reducing conditions is accompanied by an increase of the corresponding high temperature activation energy of the bulk, which is interpreted in terms of defect association or clustering.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Solid State Ionics - Volume 192, Issue 1, 16 June 2011, Pages 148–152
نویسندگان
, , , , , ,