Kahlert, H.; Frey, Friedrich; Boysen, Hans; Proffen, Th.; Mason, S.; Weppner, W.
Structural investigations of the ionic conductivity in zirconia single crystals by neutron diffraction at high temperatures and simultaneously applied electric field.
In: Ionics, Vol. 2, Nr. 2: S. 88-96
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In situ neutron diffraction studies of CaO and Y2O3 stabilized zirconia single crystals were performed at elevated temperatures and simultaneously applied DC electric field, i.e. lasting ionic current. Bragg data from Zro.85Ca0.15O1.85 (CSZ15) were collected at room temperature without electric field, at 1170 K and 1370 K without and with 3.5 V and 1.8 V, respectively, (field vector Eli[Ill]), which generated a current of 60 mA in each case. In case of Zr0.70Y 0.30Ol.85 (YSZ15) the electric field vector was directed along . At 1170 K three data sets were collected: without field, with 1.5 V (I =60 mA), and with 2.5 V (I = 120 mA). Atomic displacement parameters (a.d.p.’s) were derived in the frame of a non-Gaussian Debye-Waller factor formalism for the oxygens. Corresponding probability density function (p.d.f.) maps and pseudo potential maps were calculated. Most probable curved diffusion pathways run close to < 100 >, independent of the external field direction, applied voltage and the kind of dopant. With lasting ionic current the potential corresponding to p.d.f. > 1\% is lowered by about 0.06-0.07 eV.