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