TABLE 4.
The activation energy (simulated, E a,sim ; measured E a, exp, Yamamura (2003)) and energy barriers (E b ) for oxygen migrations in series of Ln 2Zr2O7 pyrochlores. The energy barriers for 48f-48f diffusion path for single (E b,single ) and split (E b,split ) vacancy states, as well as barrier for oxygen migration from 48f to 8a site (E b,8a ) are reported. The second set of experimental values represent the results of our fits to the data of Yamamura (2003). Values are in eV.
| Compound | E a,sim | E a, exp | E b,single | E b,split | E b,8a |
|---|---|---|---|---|---|
| La | - | 0.56/0.63 | 0.74 | - | - |
| Ce | 1.39 | - | 0.74 | - | 0.69 |
| Pr | 1.13 | - | 0.73 | - | 0.49 |
| Nd | 0.91 | 0.68/0.61 | 0.73 | - | 0.38 |
| Pm | 0.69 | - | 0.71 | 1.17 | 0.31 |
| Sm | 0.46 | 0.56/0.71 | 0.69 | 1.21 | 0.24 |
| Eu | 0.28 | 0.58/0.61 | - | 1.23 | 0.19 |
| Gd | 0.58 | 0.88/0.94 | - | 1.21 | 0.14 |