skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Structure of yttria stabilized zirconia beads produced by gel supported precipitation

Abstract

Yttria stabilized zirconia (YSZ) is one of the inert matrix candidates selected for investigation as host matrix for minor actinide (MA) transmutation. The structural properties of (Zr0.84, Y0.16)O1.92 beads prepared by a sol-gel method for MA infiltration, are characterized as calcined (850 C) and sintered (1,600 C) beads. The calcined YSZ beads are fine-grained and homogenous over the entire sphere and are surrounded by a uniform outer layer of approximately 30 {micro}m thickness. After sintering at 1,600 C, the beads are compacted to 51% of their initial volume and exhibit a granular structure. The thermal expansion is nearly linear for the calcined material, but shows a parabolic behavior for the sintered (1,400 C) beads. In addition, the thermal expansion of calcined material is 20-25% less than after sintering. During heating up to 1,400 C, two processes can be distinguished. The first occurs between 900 and 1,000 C and is related to an increase in unit cell order. The second process involves grain-growth of the less crystalline calcined material between 1,100 and 1,300 C. These results have implications for preparation of YSZ and its use as an inert MA transmutation matrix.

Authors:
 [1];  [1];  [2];  [3];  [3];  [1];  [4];  [5]
  1. Institute for Transuranium Elements, Germany
  2. EURATOM-CIEMAT, Madrid, Spain
  3. ORNL
  4. Institut fur Nukleare Entsorgung, Karlsruhe, Germany
  5. Max-Planck-Institute for Chemical Physiscs of Solids, Dresden, Germany
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Nuclear Energy (NE)
OSTI Identifier:
931815
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Materials Science; Journal Volume: 42
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ZIRCONIUM OXIDES; YTTRIUM OXIDES; MATRIX MATERIALS; MORPHOLOGY; SOL-GEL PROCESS; GRAIN GROWTH; THERMAL EXPANSION; ACTINIDES; TRANSMUTATION

Citation Formats

Walter, M., Somers, J., Fernandez, A., Specht, Eliot D, Hunn, John D, Boulet, P., Denecke, M. A., and Gobel, C. Structure of yttria stabilized zirconia beads produced by gel supported precipitation. United States: N. p., 2007. Web. doi:10.1007/s10853-006-0515-8.
Walter, M., Somers, J., Fernandez, A., Specht, Eliot D, Hunn, John D, Boulet, P., Denecke, M. A., & Gobel, C. Structure of yttria stabilized zirconia beads produced by gel supported precipitation. United States. doi:10.1007/s10853-006-0515-8.
Walter, M., Somers, J., Fernandez, A., Specht, Eliot D, Hunn, John D, Boulet, P., Denecke, M. A., and Gobel, C. Mon . "Structure of yttria stabilized zirconia beads produced by gel supported precipitation". United States. doi:10.1007/s10853-006-0515-8.
@article{osti_931815,
title = {Structure of yttria stabilized zirconia beads produced by gel supported precipitation},
author = {Walter, M. and Somers, J. and Fernandez, A. and Specht, Eliot D and Hunn, John D and Boulet, P. and Denecke, M. A. and Gobel, C.},
abstractNote = {Yttria stabilized zirconia (YSZ) is one of the inert matrix candidates selected for investigation as host matrix for minor actinide (MA) transmutation. The structural properties of (Zr0.84, Y0.16)O1.92 beads prepared by a sol-gel method for MA infiltration, are characterized as calcined (850 C) and sintered (1,600 C) beads. The calcined YSZ beads are fine-grained and homogenous over the entire sphere and are surrounded by a uniform outer layer of approximately 30 {micro}m thickness. After sintering at 1,600 C, the beads are compacted to 51% of their initial volume and exhibit a granular structure. The thermal expansion is nearly linear for the calcined material, but shows a parabolic behavior for the sintered (1,400 C) beads. In addition, the thermal expansion of calcined material is 20-25% less than after sintering. During heating up to 1,400 C, two processes can be distinguished. The first occurs between 900 and 1,000 C and is related to an increase in unit cell order. The second process involves grain-growth of the less crystalline calcined material between 1,100 and 1,300 C. These results have implications for preparation of YSZ and its use as an inert MA transmutation matrix.},
doi = {10.1007/s10853-006-0515-8},
journal = {Journal of Materials Science},
number = ,
volume = 42,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • Nanostructured platinum/yttria-stabilized zirconia (YSZ) cermet (composite of ceramics and metal) is obtained by the sol-gel method. Influences of the processing parameters on the nanostructure are experimentally studied using X-ray diffraction, field emission scanning electron microscopy, electron probe microanalysis, and nitrogen adsorption. The nanostructure of the cermet is controlled by the Pt/YSZ ratio, gelling procedure, and calcination temperature. The slower gelling or higher temperature calcination enlarges the YSZ grain size. The addition of a smaller amount of Pt or calcination at higher temperatures reduce the Brunauer-Emmett-Teller (BET) surface area when calcined at 973 K or above. The addition of a largermore » amount of Pt increases the porosity when calcined at 973 K or above. By controlling the conditions of synthesis, gelling, and Pt content, the average YSZ grain size was kept within 50 nm after calcination at 1,173 K.« less
  • Homogeneous, nanocrystalline powders of yttria-stabilized zirconia were prepared using a nonalkoxide sol-gel method. Monolithic gels, free of precipitation, were prepared by addition of propylene oxide to aqueous solutions of Zr{sup 4+} and Y{sup 3+} chlorides at room temperature. The gels were dried with supercritical CO{sub 2}(l), resulting in amorphous aerogels that crystallized into cubic stabilized ZrO{sub 2} following calcination at 500 C. The aerogels and resulting crystalline products were characterized using in-situ temperature profile X-ray diffraction, thermal analysis, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and nitrogen adsorption/desorption analysis. TEM and N{sub 2} adsorption/desorption analysis of an aerogel indicatedmore » a porous network structure with a high surface area (409 m{sup 2}/g). The crystallized yttria-stabilized zirconia maintained high surface area (159 m{sup 2}/g) upon formation of homogeneous, nanoparticles ({approx}10 nm). Ionic conductivity at 1000 C of sintered YSZ (1500 C, 3 hours) prepared by this method, was 0.13 {+-} 0.02 {Omega}{sup -1} cm{sup -1}. Activation energies for the conduction processes from 1000-550 C and 550-400 C, were 0.95 {+-} 0.09 and 1.12 {+-} 0.05 eV, respectively. This is the first reported synthesis and characterization of yttria-stabilized zirconia via an aerogel precursor.« less
  • (La{sub 0.8}Sr{sub 0.2}){sub 0.95}MnO{sub 3} and (La{sub 0.8}Sr{sub 0.2}){sub 0.95}MnO{sub 3}/YSZ gel films were deposited by a spin-coating technique on scandium-doped zirconia (ScSZ) substrate using the precursor solution prepared from La(O-i-C{sub 3}H{sub 7}){sub 3}, Sr(O-i-C{sub 3}H{sub 7}){sub 2}, Mn(O-i-C{sub 3}H{sub 7}){sub 2} and 2-methoxyethanol. By heat-treating the gel films, the membrane reactors, (La{sub 0.8}Sr{sub 0.2}){sub 0.95}MnO{sub 3} vertical bar ScSZ vertical bar Pt and (La{sub 0.8}Sr{sub 0.2}){sub 0.95}MnO{sub 3}/YSZ vertical bar ScSZ vertical bar Pt were fabricated. It was found that the pre-firing temperature affected the microstructure evolution of (La{sub 0.8}Sr{sub 0.2}){sub 0.95}MnO{sub 3} and (La{sub 0.8}Sr{sub 0.2}){sub 0.95}MnO{sub 3}/YSZmore » thin films. Pre-firing at low temperature resulted in high porosity and large grain size of the thin films. NO decomposition characteristics of the obtained membrane reactors were investigated at 600 deg. C in reactant gas, 1000 ppm of NO and 2% of oxygen. By applying a direct current to the membrane reactors, NO can be decomposed at the (La{sub 0.8}Sr{sub 0.2}){sub 0.95}MnO{sub 3} and (La{sub 0.8}Sr{sub 0.2}){sub 0.95}MnO{sub 3}/YSZ composite cathode. By incorporating YSZ into (La{sub 0.8}Sr{sub 0.2}){sub 0.95}MnO{sub 3}, the required consuming power to decompose NO could be reduced.« less
  • Three-dimensionally ordered macroporous (3-DOM) yttria-stabilized zirconia (YSZ) was prepared by aqueous organic gel method through the interstitial spaces between polystyrene spheres assembled on glass substrates. The morphologies and pore size of the porous YSZ were characterized by scanning electron microscope (SEM) and nitrogen adsorption. The thermal behavior, the phase and chemical composition of PS/YSZ composite were investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results show that porous YSZ has been formed with the pores arranged in an ordered close-packed three-dimensional structure. Ni/YSZ cermet was also prepared by immersing the 3-DOM YSZmore » into the solution of nickel nitrate and urea. The electrical conductivity of Ni/YSZ was about 400 S cm{sup -1} between 600 and 800 deg. C. - Graphical abstract: Three-dimensionally ordered macroporous yttria-stabilized zirconia (YSZ) was prepared by aqueous organic gel method through the interstitial spaces between polystyrene spheres assembled on glass substrates. The morphologies of the porous YSZ, the thermal behavior, the phase and chemical composition of polystyrene/YSZ composite were investigated. Ni/YSZ was also prepared and the electrical conductivity was measured.« less
  • Reduction of copper oxide supported on yttria-stabilized zirconia (YSZ) and {gamma}-alumina, was studied. Temperature-programmed reduction (TPR) and electron paramagnetic resonance (EPR) were used to characterize the catalysts. 68 refs., 13 figs., 5 tabs.