| Autor: |
Piticescu RR; National R&D Institute for Non-Ferrous and Rare Metals, INCDMNR-IMNR, 102 Biruintei Blvd., 077145 Pantelimon, Romania., Slobozeanu AE; National R&D Institute for Non-Ferrous and Rare Metals, INCDMNR-IMNR, 102 Biruintei Blvd., 077145 Pantelimon, Romania., Valsan SN; National R&D Institute for Non-Ferrous and Rare Metals, INCDMNR-IMNR, 102 Biruintei Blvd., 077145 Pantelimon, Romania., Ciobota CF; National R&D Institute for Non-Ferrous and Rare Metals, INCDMNR-IMNR, 102 Biruintei Blvd., 077145 Pantelimon, Romania., Ghita AN; National R&D Institute for Non-Ferrous and Rare Metals, INCDMNR-IMNR, 102 Biruintei Blvd., 077145 Pantelimon, Romania., Motoc AM; National R&D Institute for Non-Ferrous and Rare Metals, INCDMNR-IMNR, 102 Biruintei Blvd., 077145 Pantelimon, Romania., Chiriac S; National R&D Institute for Non-Ferrous and Rare Metals, INCDMNR-IMNR, 102 Biruintei Blvd., 077145 Pantelimon, Romania., Prakasam M; CNRS, Université de Bordeaux, ICMCB, UMR 5026, 87 Avenue du Docteur Schweitzer, CEDEX, 33608 Pessac, France. |
| Abstrakt: |
Zirconium dioxide (ZrO 2 ) is one of the ceramic materials with high potential in many areas of modern technologies. ZrO 2 doped with 8 wt.% (~4.5 mol%) Y 2 O 3 is a commercial powder used for obtaining stabilized zirconia materials (8 wt.% YSZ) with high temperature resistance and good ionic conductivity. During recent years it was reported the co-doping with multiple rare earth elements has a significant influence on the thermal, mechanical and ionic conductivity of zirconia, due complex grain size segregation and enhanced oxygen vacancies mobility. Different methods have been proposed to synthesize these materials. Here, we present the hydrothermal synthesis of 8 wt.% (~4.5 mol%) YSZ co-doped with 4, 6 and 8 wt.% La 2 O 3 , Nd 2 O 3 , Sm 2 O 3 and Gd 2 O 3 respectively. The crystalline phases formed during their thermal treatment in a large temperature range were analyzed by X-ray diffraction. The evolution of phase composition vs. thermal treatment temperatures shows as a major trend the formation at temperatures >1000 °C of a cubic solid solutions enriched in the rare earth oxide used for co-doping as major phase. The first results on the thermal conductivities and impedance measurements on sintered pellets obtained from powders co-doped with 8 wt.% Y and 6% Ln (Ln = La, Nd, Sm and Gd) and the corresponding activation energies are presented and discussed. The lowest thermal conductivity was obtained for La co-doped 8 wt.% YSZ while the lowest activation energy for ionic conduction for Gd co-doped 8 wt.% YSZ materials. |
