Table 1 The strain, lattice parameters, ion positions, and compressive pressure as obtained from first principle calculations using density functional theory. The ion positions obtained are used for calculating the off-centre displacement in a cell. The results simulate the experimentally observed nonmonotonic particle-size-dependence of off-centre displacement in nanoscale BiFeO3.
Strain (%) | a (Å) | c (Å) | Bi x, y, z | Fe x, y, z | O x, y, z |
|---|---|---|---|---|---|
0 | 5.446 | 13.144 | 0.0000 0.0000 −0.01244 | 0.0000 0.0000 0.21891 | 0.24436 0.89577 0.29104 |
−1.0 | 5.529 | 13.241 | 0.0000 0.0000 −0.00959 | 0.0000 0.0000 0.21896 | 0.24625 0.89726 0.29008 |
−2.0 | 5.500 | 13.472 | 0.0000 0.0000 0.00750 | 0.0000 0.0000 0.78156 | 0.01478 0.43679 0.04378 |
+1.0 | 5.539 | 12.825 | 0.0000 0.0000 −0.01461 | 0.0000 0.0000 0.21997 | 0.24855 0.89875 0.29142 |
+2.0 | 5.601 | 12.540 | 0.0000 0.0000 −0.01716 | 0.0000 0.0000 0.22091 | 0.25167 −0.09918 0.29195 |
−2.0 (0.063 GPa) | 5.500 | 13.2156 | 0.0000 0.0000 −0.01656 | 0.0000 0.0000 0.22147 | 0.25116 −0.09957 0.29257 |
−2.0 (0.7 Gpa) | 5.500 | 13.0542 | 0.0000 0.0000 −0.01659 | 0.0000 0.0000 0.22114 | 0.25082 −0.09975 0.2926 |
−2.0 (7.7 GPa) | 5.500 | 12.8468 | 0.0000 0.0000 −0.01725 | 0.0000 0.0000 0.22037 | 0.24908 0.8993 0.29216 |
