Structure, the Grain Structure, and the Dielectric Properties of Ceramics of Solid Solutions YCuxMn1 – xO3

Abstract

Solid solution YCuxMn1 – xO3 ceramics of with x = 0.05, 0.10, and 0.15 have been produced by the solid-phase reaction method with subsequent sintering by common ceramic technology. The structure, the microstructure, and the dielectric properties of the ceramics have been studied, including the measurements of the temperature–frequency dependences of the relative dielectric permittivity and the dielectric loss tangent, and also the electrical conductivity. It is found that the mainly hexagonal phase forms in the ceramics; in this case, their grain structures are inhomogeneous and their synthesis occurs with the formation of liquid phases of eutectic origin. It is shown that the anomalous behavior of the dielectric characteristics at T = 30–200°C in all these ceramics is related to the effects of the interlayer polarization, and at T = 222°C (x = 0.05), 234°C (x = 0.10), and 247°C (x = 0.15), with the “isostructural” transition that is intermediate one between the ferroelectric and paraelectric phases.