Publication | Closed Access
Mixed-valence manganites
551
Citations
0
References
2009
Year
Magnetic PropertiesColossal MagnetoresistanceEngineeringMagnetic TexturesChemistryMagnetic MaterialsMagnetoresistanceMagnetismMultiferroicsQuantum MaterialsOxide HeterostructuresMaterials ScienceLow-dimensional SystemsMagnetic MaterialFerromagnetismNatural SciencesApplied PhysicsCondensed Matter PhysicsMagnetic Polaron FormationThin FilmsFunctional Materials
Mixed‑valence manganese oxides (R1‑χAχ)MnO3 display a rich array of crystallographic, electronic and magnetic phases and have historically inspired concepts such as double exchange and the Jahn‑Teller polaron. This review surveys the literature on mixed‑valence manganites, contextualizing recent findings within the established knowledge of these materials and related magnetic semiconductors. The review examines electronic ground states, metal‑insulator transitions driven by temperature, pressure and magnetic field, transport mechanisms, polaron formation, magnetic localization, cation disorder, the Jahn‑Teller effect, sample preparation, and properties of related ferromagnetic oxides. Recent thin‑film studies reveal colossal magnetoresistance near the Curie temperature, dense granular magnetoresistance, and optically induced magnetic phase transitions.
Mixed-valence manganese oxides (R1-χAχ)MnO3 (R=rare-earth cation, A=alkali or alkaline earth cation), with a structure similar to that of perovskite CaTiO3, exhibit a rich variety of crystallographic, electronic and magnetic phases. Historically they led to the formulation of new physical concepts such as double exchange and the Jahn-Teller polaron. More recent work on thin films has revealed new phenomena, including colossal magnetoresistance near the Curie temperature, dense granular magnetoresistance and optically-induced magnetic phase transitions. This review gives an account of the literature on mixed-valence manganites, placing new results in the context of established knowledge of these materials, and other magnetic semiconductors. Issues addressed include the nature of the electronic ground states, the metal-insulator transition as a function of temperature, pressure and applied magnetic field, the electronic transport mechanisms, dielectric and magnetic polaron formation, magnetic localization, the role of cation disorder and the Jahn-Teller effect. Sample preparation, and the properties of related ferromagnetic oxides are also discussed.