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- Ahmed, Istaq, 1972, et al.
(författare)
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Synthesis and structural characterization of perovskite type proton conducting BaZr1-xInxO3-delta (0.0 <= x <= 0.75)
- 2006
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Ingår i: Solid State Ionics. - : Elsevier BV. - 0167-2738 .- 1872-7689. ; 177:17-18, s. 1395-1403
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Tidskriftsartikel (refereegranskat)abstract
- Solid state sintering has been used to prepare the cubic perovskite structured compounds BaZr1-xInxO3-delta (0.0 <= x <= 0.75). Analysis of X-ray powder diffraction (XRPD) data reveals that the unit cell parameter, a, increases linearly with an increased Indium concentration. XRPD data was also used to demonstrate the completion of sample hydration, which was reached when the materials showed a set of single-phase Bragg-peaks. Dynamic thermogravimetric analysis (TGA) data showed that approx. 89% of the total number of available oxygen vacancies can be filled in BaZr1-xInxO3-delta for x=0.50, and that the maximum water uptake occurs below 300 degrees C. Rietveld analysis of the room temperature neutron powder diffraction (NPD) data confirmed the average cubic symmetry (space group Pm-3m), and an expansion of the unit cell parameter after the hydration reaction. The strong O-H stretch band, 2500-3500 cm(-1), in the infrared absorbance spectrum clearly manifests the presence of protons in the hydrated material. Proton conductivity of hydrated BaZr1-xInxO3-delta, x=0.75 was investigated during heating and cooling cycles under dry argon atmosphere. The total conductivity during the heating cycle was nearly two orders of magnitude greater than that of cooling cycle at 300 degrees C, whilst these values were similar at higher temperatures i.e. T > 600 degrees C.
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| 2. |
- Karlsson, Maths, 1978, et al.
(författare)
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Using Neutron Spin-Echo To Investigate Proton Dynamics in Proton-Conducting Perovskites
- 2010
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 1520-5002 .- 0897-4756. ; 22:3, s. 740-742
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Tidskriftsartikel (refereegranskat)abstract
- The applicability and potential of neutron spin-echo (NSE) to study proton dynamics in proton-conducting ceramics was studied. The experiment was performed on hydrated BaZr 0,90 Y 0.10 O 2.95 (10Y:BZO), a cubic perovskite with a relatively high proton conductivity. The NSE experiment was performed at the IN15 spectrometer at Institut Laue-Langevin (ILL) in Grenoble, France. The relaxation rate for two Q-values for the temperature 563 K was determined. The first-principles calculations were carried out within the framework of density functional theory (DFT). The calculated diffusion harriers far from Y-dopants are found to he 0.20 and 0.18 eV for the proton transfer and hydroxyl rotation motion, respectively. The binding energy to a Y-dopant is 0.16 eV, and the influence of the Y-dopant on the energetics for the proton is quite extended in space, including both the first and the second coordination shells.
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