Impurity diffusion of cerium and gadolinium in single- and polycrystalline yttria-stabilized zirconia

Abstract

Yttria-stabilized zirconia (YSZ) ceramic is considered as an attractive material for solid oxide fuel cells or for nuclear applications such as inert matrix for the destruction of excess plutonium and host material for nuclear waste storage. Long term properties as phase stability depend on cation diffusion. Therefore, the present work is focused on the diffusion study of Ce and Gd in YSZ single crystals and high density polycrystals. A thin film of Ce or Gd was deposited either by spin-coating method or by physical vapour deposition on the surface of polished samples. The diffusion experiments were performed from 1173 to 1673 K under air. The Ce or Gd diffusion profiles were determined by secondary ion mass spectrometry. The analysis of the penetration profiles led to the determination of bulk diffusion (D b) in single crystals and effective (D eff), bulk and grain boundary diffusion coefficients (D gb) were determined in polycrystals. The dependence of diffusion coefficients on temperature is described by means of Arrhenius equations and the diffusivity is compared with literature.

Fabrication of oxide pellets containing lumped Gd2O3using Y2O3-stabilized ZrO2for burnable absorber fuel applications

“…Eight weight percent yttria-stabilized zirconia (8YSZ) was used as a surrogate for UO 2 . 30 The measured diffusion coefficients were found to be 5.2 × 10 −17 , 6.6 × 10 −16 , and 5.2 × 10 −15 . The studies about the sintering behavior of UO 2 in the H 2 atmosphere have shown that UO 2 has an activation energy of 429 ± 8 kJ/mol in the temperature range 1150°C to 1400°C.…”

“…28,29 The diffusion coefficient of Gd +3 ion into 8YSZ matrix was measured by performing diffusion experiments between Gd 2 O 3 and 8YSZ at 1200°C, 1300°C, and 1400°C. 30 The measured diffusion coefficients were found to be 5.2 × 10 −17 , 6.6 × 10 −16 , and 5.2 × 10 −15 . 30 The reported diffusion coefficients of Gd +2 into UO 2 matrix at the corresponding temperature range were 2.67 × 10 −17 , 7.54 × 10 −17 , and 1.88 × 10 −16 , respectively.…”

“…30 The measured diffusion coefficients were found to be 5.2 × 10 −17 , 6.6 × 10 −16 , and 5.2 × 10 −15 . 30 The reported diffusion coefficients of Gd +2 into UO 2 matrix at the corresponding temperature range were 2.67 × 10 −17 , 7.54 × 10 −17 , and 1.88 × 10 −16 , respectively. 31 Yttria-stabilized zirconia was previously used as a surrogate for UO 2 in the fabrication studies of new fuel designs such spherical fuel element and inert matrix fuel, as well as in the fabrication studies of a porous oxide structure that resembles the high burnup structure of UO 2 .…”

“…Both 8YSZ and UO 2 have a fluorite structure and high melting points. 30 The reported diffusion coefficients of Gd +2 into UO 2 matrix at the corresponding temperature range were 2.67 × 10 −17 , 7.54 × 10 −17 , and 1.88 × 10 −16 , respectively. 26 Lahiri et al 27 have studied the sintering behavior of UO 2 in the H 2 atmosphere in the temperature range 950°C to 1200°C and found that UO 2 experiences a change in the diffusion mechanism from grain boundary diffusion to volume diffusion at approximately 1000°C.…”

Investigation of NdxY0.25–xZr0.75O1.88 inert matrix fuel materials made by a co-precipitation synthetic route

“…[23][24][25][26] The cubic structure can be stabilized by adding an aliovalent cation, and Y 3+ has been commonly used as the dopant ion. 22,[27][28][29][30] The size difference between Y 3+ and Zr 4+ as well as oxygen vacancies generated by charge balancing requirements act to stabilize the fluorite structure. 19,31 In doped cubic zirconia systems, the dopant and Zr are randomly distributed in the Zr 4a site.…”