Enhanced dielectric properties of CaMnO₃/La_0.5Sr_0.5CrO₃/CaMnO₃ laminated and co-sintered ceramics

The high-capacity and quality ceramic materials have the potential of miniaturization and convenience for electronic components. In this work, CaMnO₃ (CMO) and La_0.5Sr_0.5CrO₃ (LSCO) powders are prepared by the traditional solid phase method and the laminated LSCO/CMO/LSCO samples are made via the rolling process. It can be found that the CMO and LSCO layers are clearly kept flat in co-sintered samples by SEM analysis. The capacity value of >0.1 μF/cm²(<100 Hz), the obviously reduced dielectric loss and the increased insulation resistivity are achieved in LSCO/CMO/LSCO samples at room temperature. Through the characterization of complex impedance spectroscopy, XRD and XPS, the ameliorative dielectric performance mainly depends on the interface between CMO and LSCO layers, which produces the high resistance value and blocks the long-range transition of the carriers. This phenomenon has an important significance for the development and application of large-capacity and co-sintered ceramic capacitors.