In order to clarify the diffusion of oxide-ion vacancies in this perovskite-type oxide, the tracer diffusion coefficient of oxide ions in La1-xSrxFeO3 (x = 0.1, 0.25 or 0.4) single crystals (table 86) was found by using an 18O/16O tracer gas-phase analysis method. The correlation factor for a vacancy diffusion mechanism in a perovskite-type anion sub-lattice was calculated to be 0.69. Using this value and the non-stoichiometric data, the diffusion coefficient of the oxide ion vacancies was estimated (tables 87). The diffusivity of oxide ions in this perovskite-type oxide was comparable to that in fluorite-type oxides.
T.Ishigaki, S.Yamauchi, K.Kishio, J.Mizusaki, K.Fueki: Journal of Solid State Chemistry, 1988, 73[1], 179-87
Table 86
Tracer Diffusion of Oxide Ions in La1-xSrxFeO3
(Oxygen partial pressure = 6.5kPa)
Temperature (C) | x | D (cm2/s) |
1100 | 0.1 | 2.86 x 10-8 |
1050 | 0.1 | 2.34 x 10-8 |
1000 | 0.1 | 1.10 x 10-8 |
950 | 0.1 | 4.89 x 10-9 |
900 | 0.1 | 3.22 x 10-9 |
1050 | 0.25 | 2.70 x 10-7 |
1000 | 0.25 | 1.25 x 10-7 |
950 | 0.25 | 6.70 x 10-8 |
900 | 0.25 | 3.37 x 10-8 |
1000 | 0.4 | 5.88 x 10-7 |
Table 87
Diffusion Coefficient of Oxide Ion Vacancies in La1-xSrxFeO3
(Oxygen partial pressure = 6.5kpa)
Temperature (C) | x | D (cm2/s) |
1100 | 0.1 | 1.12 x 10-5 |
1050 | 0.1 | 1.21 x 10-5 |
1000 | 0.1 | 7.41 x 10-6 |
950 | 0.1 | 4.59 x 10-6 |
900 | 0.1 | 4.49 x 10-6 |
1050 | 0.25 | 2.36 x 10-5 |
1000 | 0.25 | 1.32 x 10-5 |
950 | 0.25 | 6.18 x 10-6 |
900 | 0.25 | 6.08 x 10-6 |
1000 | 0.4 | 1.95 x 10-5 |