Definition: Lanthanum manganite is a chemical compound with the formula LaMnO₃. It is an inorganic perovskite-type oxide composed of lanthanum, manganese, and oxygen.
Overview: Lanthanum manganite belongs to the family of perovskite oxides, which are known for their diverse electronic and magnetic properties. It is primarily studied for its role as a parent compound of doped manganites that exhibit colossal magnetoresistance (CMR), a phenomenon characterized by a significant change in electrical resistance in response to an applied magnetic field. These materials are of interest for potential applications in magnetic sensors and spintronic devices.
Etymology/Origin: The name "lanthanum manganite" is derived from its constituent elements: lanthanum (La), a rare-earth element, and manganese (Mn), a transition metal, with the "-ite" suffix commonly used in inorganic chemistry to denote an oxide or oxyanion compound.
Characteristics: Lanthanum manganite crystallizes in an orthorhombic perovskite structure at room temperature, though structural distortions due to tilting of MnO₆ octahedra are common. It is an antiferromagnetic insulator with a Neél temperature of approximately 140 K. The material exhibits a Jahn-Teller distortion due to the Mn³⁺ ion's electronic configuration, contributing to its insulating behavior and structural asymmetry. Doping lanthanum manganite with divalent cations such as strontium (Sr²⁺) or calcium (Ca²⁺) on the La-site can induce metal-insulator transitions and ferromagnetism, leading to the CMR effect.
Related Topics:
- Perovskite structure
- Colossal magnetoresistance (CMR)
- Doped manganites (e.g., La₁₋ₓSrₓMnO₃)
- Transition metal oxides
- Strongly correlated electron systems
- Magnetic materials
- Solid oxide fuel cells (as a potential cathode material in modified forms)
Accuracy note: All information provided is consistent with established scientific literature on lanthanum manganite and related perovskite oxides.