کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1298402 1498351 2010 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Grain core and grain boundary electrical/dielectric properties of yttria-doped tetragonal zirconia polycrystal (TZP) nanoceramics
موضوعات مرتبط
مهندسی و علوم پایه شیمی الکتروشیمی
پیش نمایش صفحه اول مقاله
Grain core and grain boundary electrical/dielectric properties of yttria-doped tetragonal zirconia polycrystal (TZP) nanoceramics
چکیده انگلیسی

Bulk samples of nanocrystalline tetragonal zirconia polycrystal (TZP), with 3 mol.% Y2O3, were fabricated over a range of average grain sizes (16–70 nm) by partial sintering. The samples were measured using AC-impedance spectroscopy over a range of temperatures, and porosity-corrected electrical results were interpreted in terms of microstructural models. Whereas the conventional brick layer model (BLM) significantly overestimated the specific grain boundary conductivity at the nanoscale, our recently developed nano-Grain Composite Model (n-GCM) allowed accurate determination of local grain boundary and grain core conductivities, grain boundary dielectric constants, and electrical grain boundary widths. Grain core effective dielectric constants were also separately measured on microcrystalline samples over a range of temperatures for use in the n-GCM analysis. It was found that TZP exhibits an enhanced local grain boundary conductivity at the nanoscale, but the enhancement is insufficient to improve the total conductivity. Rather, total conductivity decreased with decreasing grain size. Results were compared with those for nanocrystalline yttria-stabilized zirconia (8 mol.% Y2O3, YSZ).

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Solid State Ionics - Volume 181, Issues 5–7, 11 March 2010, Pages 276–284
نویسندگان
, ,