  The rare-earth-metal-oxide based electronic materials were produced via a
conventional mixed-oxide route. Thermal analysis, XRD and SEM were used to
follow phase evolution and demonstrate the phase purity. Analytical TEM were
used to analyze crystal structural defects and to track the presence of
secondary phases, especially at grain boundaries. A crystal structure
determination was also performed. Phonon modes were analyzed with FTIR and
Raman spectroscopies and correlated with the origin of dielectric permittivity
({\epsilon}r) and radiation losses (tan {\delta}) characteristics. In some
compound and mixed compound Raman band mode exist, but this band is absent in
simple perovskite indicating that this band is associated with distribution of
B-site cations ordering. Some of compound shows long range order in B-site,
while it does not present in other material. A photo-acoustic sampling
technique in conjunction with the FTIR spectroscopy was employed, allowing the
analysis of neat materials with minimal sample preparation. Measurements of the
quality factor (Qf), {\epsilon}r and the temperature coefficient of the
resonant frequency ({\tau}f) characteristics were made at the microwave
resonant frequency using a vector or network analyzer.
  These perovskite have low tolerance factor because of considerable size
misfit of constituting atoms. For determination of atomic size and
characterization of constitution atoms, the test of samples and Rietveld
refinement using GSAS programs were used to do this examination. These
materials have attractive dielectric properties are being evaluated extensively
for substrates for multi-chip-module (MCM) devices and microwave
telecommunications.
