S. Stefanovich et al., PROCESSING AND CHARACTERIZATION OF FERRO PIEZOELECTRICS IN THE STILLWELLITE FAMILY/, Ferroelectrics, 201(1-4), 1997, pp. 285-294
New family of stillwellite-like (CeBSiO5, sp.gr. P3(1)) ferroelectric
borosilicates and borogermanates is found, their properties and possib
le applications are discussed. Borophosphates ABPO(5) (sp.gr. P3(1)21,
A=Ca, Sr, Ba, Pb) which are very similar in structure are classified
as piezoelectrics. Structural, dielectric and optical non-linear chara
cteristics of new ferroelectrics are investigated on single crystals o
btained either by flux or Czochralski methods. Optical SHG data on pow
ders and ceramics in an interval 300-1300 K, combined with dielectric
and Xray data, allow to define ferroelectric phase boundaries on the x
-T phase diagrams. Crystallization from glasses in ternary systems Ln(
2)O(3)-B2O3-SiO2 (GeO2) is investigated and good opportunity is demons
trated for formation of polar glass-ceramic textures with ferroelectri
c and pyroelectric properties.