Table 7. List of refined parameters for CoFe2O4 samples prepared with different Co-containing salts.
The refinement model uses a combination of in-house PXRD data (Cu Kα) and NPD data from HRPT. Occupancies of the Td and Oh sites were refined separately. The saturation magnetization extracted from VSM measurements (
) is tabulated along with the calculated macroscopic magnetization (M
neutron). None of this work has been previously published.
| Co(Ac)2 | Co(NO3)2 | CoCl2 | |
|---|---|---|---|
| Unit cell (Å) | 8.4031 (2) | 8.4058 (2) | 8.4060 (2) |
| Crystallite size (nm) | 10.2 (8) | 10.6 (8) | 10.7 (8) |
| x (O) | 0.2430 (1) | 0.2430 (1) | 0.2430 (1) |
| B ov (Å2) | 0.65 (1) | 0.74 (1) | 0.69 (1) |
| Occ(Co2+)Td (%) | 39 (1) | 40 (1) | 39 (1) |
| Occ(Fe3+)Td (%) | 61 (1) | 60 (1) | 61 (1) |
| Occ(Co2+)Oh (%) | 39 (1) | 40 (1) | 40 (1) |
| Occ(Fe3+)Oh (%) | 61 (1) | 60 (1) | 60 (1) |
| (Co2+ 1−x Fe3+ x )Td | (Co0.39 (1)Fe0.61 (1)) | (Co0.40 (1)Fe0.60 (1)) | (Co0.39 (1)Fe0.61 (1)) |
| [Co2+ y Fe3+ 2−y ]Oh | [Co0.78 (1)Fe1.22 (2)] | [Co0.80 (1)Fe1.20 (2)] | [Co0.80 (1)Fe1.20 (2)] |
| Co:Fe ratio | 1.17 (1):1.83 (2) | 1.20 (1):1.80 (2) | 1.19 (1):1.81 (2) |
| R x(Co2+)Oh (μB) | 2.32 (1) | 2.26 (1) | 2.29 (1) |
| R x(Fe3+)Oh (μB) | 3.87 (2) | 3.77 (2) | 3.81 (2) |
| m (μB f.u.−1) | 3.3 (1) | 3.2 (1) | 3.2 (1) |
| M neutron (A m2 kg−1) | 77 (2) | 75 (2) | 76 (2) |
|
(A m2 kg−1) |
66.81 | 69.32 | 66.67 |
| R wp (%) | 8.6/9.8 | 9.1/9.5 | 8.9/9.3 |
| χ2 | 2.9/1.3 | 3.1/1.4 | 3.0/1.3 |
| R Bragg (%) | 2.9/4.3 | 3.5/2.4 | 3.4/3.3 |
| R mag (%) | 4.9/– | 5.6/– | 5.5/– |
| #reflections | 31/21 | 31/21 | 31/21 |