Abstract
The process of formation of the Ruddlesden-Popper phases LnSr 2Mn 2O 7 (Ln = La, Nd, Gd) was investigated by means of X-ray diffraction, thermal analysis and microprobe analysis. Two parallel pathways were found for the reaction. The first one includes the formation of the intermediate K 2NiF 4-type compound by interaction of Sr 7Mn 4O 15 and perovskite-type solid solution (Ln,Sr)MnO 3, while in the second one the K 2NiF 4-type intermediate is formed during the reaction of the same perovskite-type solid solution with the corresponding rare earth oxide. This result gives an explanation for the formation of two phases with slightly different cationic compositions. The kinetics of the reaction was investigated for both mechanisms resulting in determination of their relative contribution to the final composition. Pure NdSr 2Mn 2O 7 was obtained using a step-by-step process according to the first mechanism, and the magnetic properties of this phase were investigated.
| Original language | English |
|---|---|
| Pages (from-to) | 4156-4160 |
| Number of pages | 5 |
| Journal | Materials research bulletin |
| Volume | 47 |
| Issue number | 12 |
| DOIs | |
| Publication status | Published - 1 Dec 2012 |
| Externally published | Yes |
Keywords
- Layered compounds
- Differential scanning calorimetry (DSC)
- X-ray diffraction
- Crystal structure
- Magnetic properties