Applied Physics Letters · 2005 · 81 citations · 8 references
Natural SciencesMaterials SciencePhysicsCondensed Matter PhysicsMaterials PhysicsSolid State PhysicsElectronic Band StructureElectronic Material CharacterizationElectronic Transport ModelingMagnetism In SolidsOxide SemiconductorsSemiconductor PhysicsConductionElectron HoppingElectron Transport In SolidsHopping ConductionHopping TransportSmall-polaron TransportThermistorsVariable-range Hopping
The resistance versus temperature (R–T) characteristics of NiMn2O4+δ thermistors have been analyzed. In the literature, electron transport in manganate spinels is commonly described by a small-polaron model for nearest neighbor hopping, but variable range hopping (VRH) has not been considered so far. In this study differentiated R–T data were analyzed, allowing a clear distinction between different modes of hopping. In pressed pellets and thick screen printed films conduction was well described by a VRH model for a parabolic density of states, which was confirmed by scanning tunneling spectroscopy.
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