Table 1.
Results of the analysis of the Mössbauer spectra of nanoparticles. δA,B is the isomer shift for iron atoms in the (A) and [B] lattice sites; q is the quadrupole coupling constant; Hhf is the hyperfine magnetic field at the 57Fe nucleus.
| δA, mm/s | Hhf A, T | δB, mm/s | Hhf B, T | q, mm/s | KV/kB, K | K, erg/cm3 | ΔD/D0 | |
|---|---|---|---|---|---|---|---|---|
| Bulk γ-Fe2O3 at 8 K [40] |
0.37 (2) | 51.4 (2) | 0.47 (2) | 52.8 (2) | - | - | * 4.7 × 104 | - |
| Nano (12 nm) at 7 K |
0.37 6(2) | 51.95 (5) | 0.471 (3) | 54.30 (5) | −0.35 (2) | 1064 (73) | 2.0 × 105 | 0.268 (20) |
| Nano (12 nm) at 297 K |
0.307 (3) | 49.54 (20) | 0.322 (20) | 49.91 (20) | −0.35 (5) | 484 (20) | 0.9 × 105 | 0.276 (5) |
* K value for bulk γ-Fe2O3 was taken from [40].