Danilo Suvorov, Matjaž Valant, Boštjan Jančar and Srečo D. Škapin
“Jožef  Stefan”  Institute, Jamova 39, SI-1001 Ljubljana, Slovenia
 

ABSTRACT

Ceramics based on CaTiO₃–NdAlO₃ solid solutions were synthesized in order to study their dielectric microwave properties. Microstructural analysis was performed with scanning electron microscopy (SEM) and transmission electron microscopy (TEM) using different analytical methods such as energy-dispersive X-ray spectroscopy (EDXS). It was observed that the heating conditions during sintering and subsequent cooling strongly affect the microstructural development of the CaTiO3–NdAlO3-based ceramics. Various types and concentrations of structural defects were identified, for example, dislocations, twins and/or antiphase boundaries. All such defects resulted in a degradation of the dielectric microwave properties, in particular the quality factor Q. The dielectric properties of CaTiO₃–NdAlO₃ -based ceramics can be improved by an appropriate thermal treatment. Some of the microwave dielectric properties can also be improved by using iso- or alio-valent dopants.