Giant Dielectric Permittivity and Colossal Magnetocapacitance Effect in Complex Manganites with High Conductivity

摘要

The temperature dependences of the dielectric properties and conductivity of the La_(1-x)Sr_xMnO_3 single crystals (x = 0.1, 0.11, 0.125) are investigated in a wide temperature range. It is found that the giant dielectric permittivity arises due to the pre-percolation regime of the charge separation. These single crystals display also the colossal magnetocapacitance effect. The features of the temperature dependence of these dielectric properties are explained by the nanoscale dynamic inhomogeneties appearing due to the charge and spin ordering.