Nitrogen diffusion in nitrogen-doped yttria stabilised zirconia

Nitrogen self-diffusion was measured in single crystalline nitrogen-doped yttria-stabilised zirconia (YZrON) containing 10 mol% yttrium oxide. Samples containing two different nitrogen contents (5 and 6 mol% N on the anion sublattice) were investigated as a function of temperature (650–1000 K) using implanted 15N as a stable tracer. For a given temperature, the nitrogen diffusivity was nearly independent of the nitrogen content in the nitrogen-doped yttria-stabilised zirconia, which can be only partially understood using defect chemistry. The activation enthalpy of nitrogen diffusion was between 2 and 2.5 eV with a preexponential factor of the order of 100 cm2 s−1, which corresponds to a migration entropy of 5 kB. The surface exchange reaction between nitrogen and the oxonitride surface was investigated at 1073 K using 200 mbar gaseous 15N2 and was found to be slow but considerable. Decreasing the oxygen content in the gas phase can enhance the nitrogen incorporation into the oxonitrides.Instituto de Física La Plat

SIMS study of transition metal transport in single crystalline yttria stabilised zirconia

The diffusion of Co, Fe and Ni in single crystalline yttria stabilized zirconia (YSZ) containing 9.5 mol% Y2O3 was studied in the temperature range between 1373 and 1673 K using secondary ion mass spectroscopy. Two different types of diffusion sources were used: thin oxide layers made by spin coating with a thickness of about 150 nm containing all three transition metals (Fe, Co and Ni) on YSZ single crystals and YSZ single crystals implanted with Ni (3 × 1016 ions cm-2, 100 keV) at a mean depth of 45 nm. The determined diffusivities varied in the order D(Fe) < D(Co) < D(Ni). Activation energies for the diffusion of the elements were determined to.be 2.7 ± 0.4 eV, 3.9 ± 0.3 eV and 3.8 ± 0.3 eV for Fe, Co and Ni (3.6 ± 0.5 eV for implanted Ni), respectively. For the latter ion, the value of the activation energy was practically independent of the type of Ni source. The values for all elements were lower by 1-2 eV than for the host cation (Y and Zr) diffusion.Fil: Argirusis, Christos. Technische Universität Clausthal; AlemaniaFil: Taylor, Marcela Andrea. Technische Universität Clausthal; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Kilo, Martin. Technische Universität Clausthal; AlemaniaFil: Borchardt, Günter. Technische Universität Clausthal; AlemaniaFil: Jomard, François. Centre National de la Recherche Scientifique; FranciaFil: Lesage, Bernard. Université Paris Sud; FranciaFil: Kaïtasov, Odile. Université Paris Sud; Franci

Nitrogen diffusion in nitrogen-doped yttria stabilised zirconia

Nitrogen self-diffusion was measured in single crystalline nitrogen-doped yttria-stabilised zirconia (YZrON) containing 10 mol% yttrium oxide. Samples containing two different nitrogen contents (5 and 6 mol% N on the anion sublattice) were investigated as a function of temperature (650-1000 K) using implanted N as a stable tracer. For a given temperature, the nitrogen diffusivity was nearly independent of the nitrogen content in the nitrogen-doped yttria-stabilised zirconia, which can be only partially understood using defect chemistry. The activation enthalpy of nitrogen diffusion was between 2 and 2.5 eV with a preexponential factor of the order of 100 cm2 s-1, which corresponds to a migration entropy of 5 kB. The surface exchange reaction between nitrogen and the oxonitride surface was investigated at 1073 K using 200 mbar gaseous 15N2 and was found to be slow but considerable. Decreasing the oxygen content in the gas phase can enhance the nitrogen incorporation into the oxonitrides.Fil: Kilo, Martin. Technische Universität Clausthal; AlemaniaFil: Taylor, Marcela Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Technische Universität Clausthal; AlemaniaFil: Argirusis, Christos. Technische Universität Clausthal; AlemaniaFil: Borchardt, Günter. Technische Universität Clausthal; AlemaniaFil: Lerch, Martin. Technishe Universitat Berlin; AlemaniaFil: Kaïtasov, Odile. Universite Paris-sud Xi; FranciaFil: Lesage, Bernard. Centre de Sciences Nucléaires Et de Sciences de la Matière; Franci