Metal-Insulator Transitions in CuInGaO4 and CuIn2Ga2O7 Homogeneous Phases
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Abstract
The compounds CuInGaO4 and CuIn2Ga2O7 crystallize in the (LnFeO3)nFeO layer structure. In this paper, the electrical properties of CuInGaO4 and CuIn2Ga2O7 ceramics prepared by solid-state synthesis were examined. Both compounds exhibited a dramatic change in physical properties across a second-order phase transition at 226 K identified by calorimetry experiments. Above this temperature, the conductivity increased over four orders of magnitude and the relative permittivity increased and became strongly dispersive. These observations are explained on the basis of a hole-hopping mechanism in the Cu layers within the (LnFeO3)nFeO cystal structure.
Keywords: Ceramics, Electrical properties, Electroceramics, Semiconductors
Corresponding author: E-mail: naratipcmu@yahoo.com
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