کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10632172 | 992391 | 2005 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Transport properties and thermal expansion of La2Mo2O9-based solid electrolytes
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The oxygen ion transference numbers of La1.7Bi0.3Mo2O9, La2Mo1.7W0.3O9 and La2Mo1.95V0.05O9 ceramics, determined by modified faradaic efficiency and e.m.f. methods at 973-1173Â K, vary in the range 0.995-0.977 in air, decreasing when temperature increases. The activation energies for the ionic and electronic transport are 61-71Â kJ/mol and 123-141Â kJ/mol, respectively. Reducing oxygen chemical potential leads to increasing n-type electronic contribution to the total conductivity, which remains, however, essentially p(O2)-independent down to oxygen pressures of 10â4-10â3Â atm and exhibits reversible drop on further reduction, probably due to phase decomposition. Doping La2Mo2O9 with calcium results in segregation of a CaMoO4-based phase, accompanied with increasing electronic transport. The average thermal expansion coefficients of La2Mo2O9-based materials, calculated from dilatometric data in air, are (14.4-14.8)Â ÃÂ 10â6Â Kâ1 at 300-700Â K and (16.4-22.5)Â ÃÂ 10â6Â Kâ1 at 700-1070Â K.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Materials Research Bulletin - Volume 40, Issue 2, 15 February 2005, Pages 361-371
Journal: Materials Research Bulletin - Volume 40, Issue 2, 15 February 2005, Pages 361-371
نویسندگان
I.P. Marozau, A.L. Shaula, V.V. Kharton, N.P. Vyshatko, A.P. Viskup, J.R. Frade, F.M.B. Marques,