Abstract
Doping of the Mn-site in Ln1-yAyMn1-xMxO3 manganites has been extensively investigated. For the manganites exhibiting a Curie temperature (TC) these substitutions depress TC. However, the effect on TC is doping-element dependent. It decreases from dTC/dx = -25 K %-1 for M = Fe down to dTC/dx ∼ 0 K %-1 for M = Cr in the series Sm0.56Sr0.44Mn1-xMxO3. The peculiar role of chromium doping is also shown in the case of the charge-ordered Ln0.5Ca0.5MnO3-substituted manganites that are characterized by low average cationic size on the A-site and cationic size mismatch. For the latter, metal-insulator transitions together with CMR properties are induced by Cr and to a smaller extent by Co and Ni. The hindering of the charge-ordering establishment by these 'impurity effects' is also observed in the case of the two-dimensional manganites La0.5Sr1.5MnO4 and LaSr2Mn2O7. The highest efficiency of Cr among all doping elements may be ascribed to the similar t3 2g electronic configurations of Cr3+ and Mn4+ which allow a double-exchange between the Cr3+ and Mn3+ species.
Original language | English |
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Pages (from-to) | 1635-1659 |
Number of pages | 25 |
Journal | Philosophical Transactions of the Royal Society of London A. Mathematical, Physical and Engineering Sciences |
Volume | 356 |
Issue number | 1742 |
DOIs | |
Publication status | Published - 15 Jul 1998 |
Externally published | Yes |
Keywords
- Antiferromagnetism
- Ferromagnetism
- Insulator-metal
- Magnetoresistance
- Manganite
- Mn-site doping