Sintering of zirconia-based nanomaterials studied by variable-energy slow-positron beam

13th International Workshop on Slow Positron Beam Techniques and Applications

Prochazka, I.^1 ; Cizek, J.^1 ; Melikhova, O.^1 ; Anwand, W.^2 ; Brauer, G.^2 ; Konstantinova, T.E.^3 ; Danilenko, I.A.^3

Charles University in Prague, Faculty of Mathematics and Physics, Department of Low Temperature Physics, V Holesovickach 2, CZ-180 00 Raha 8, Czech Republic^1

Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, POB 51 01 19, D 01314 Dresden, Germany^2

National Academy of Sciences of Ukraine, Donetsk Institute for Physics and Engineering Named after O O Galkin, Luxemburg Street 72, 83114 Donetsk, Ukraine^3

关键词: Co-doped;    Doppler;    Mean particle size;    Nano powders;    Positron energy;    Shape parameters;    Slow positron beam;    Subsurface layer;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/505/1/012020/pdf
DOI  :  10.1088/1742-6596/505/1/012020

来源: IOP

【 摘 要 】

A variable-energy slow-positron beam was applied to the investigations of the tetragonal yttria-stabilised zirconia (YSZ), the YSZ co-doped with small amount of Cr2O3. The initial nanopowders exhibiting the mean particle size of 20 nm were prepared by co-precipitation technique. Prior the sintering, the nanopowders were calcined and compacted using a pressure of 500 MPa. The ordinary shape parameters of the Doppler-broadened annihilation peak and the relative positronium 3γ-fractions were determined as functions of positron energy. The results are consistent with a remarkable sintering-induced grain growth and disappearance of porosity which is driven out from the sample interior toward a thin subsurface layer.