Title :
Microstructure and properties of Cr2O3 doped lead titanate piezoceramics
Author :
Wu, Long ; Lee, Yi-Yeh ; Liang, Chich-Kow
Author_Institution :
Dept. of Electr. Eng., Nat. Cheng Kung Univ., Tainan, Taiwan
fDate :
30 Aug-2 Sep 1992
Abstract :
The effect of Cr2O3 additives (0-0.6 wt.%) on the microstructure and electrical properties of Pb0.88Ln 0.08 (Ti0.98Mn0.02)O3 ceramics, where Ln=Nd, La, is studied. In Nd-modified PT (lead titanate) ceramics, the chromium ions enter into the lattice of the perovskite structure. They behave as a grain growth promoter and accelerate densification in microstructure, and they also act as a hardener which favors higher mechanical quality factor, lower dielectric loss, and lower electrical resistivity. In the La-modified PT ceramics, with increasing Cr2O3 additives the tetragonality and the Curie temperature remains nearly unchanged. Thus, the chromium ions perhaps tend to mostly segregate at the grain boundaries and to act as grain growth inhibitors and binders, being responsible for increases in porosity, dielectric constant, ε33T, and electrical resistivity
Keywords :
X-ray diffraction examination of materials; ceramics; chromium compounds; dielectric losses; electrical conductivity of crystalline semiconductors and insulators; ferroelectric Curie temperature; grain boundaries; grain growth; grain size; lead compounds; permittivity; piezoelectric materials; porosity; scanning electron microscope examination of materials; 1200 C; 25 to 500 C; 880 C; Curie temperature; PbLaTiO3MnO3:Cr2O3; PbNdTiO3MnO3:Cr2O3; SEM; X-ray diffraction; densification; dielectric constant; dielectric loss; electrical resistivity; grain boundaries; grain growth inhibitors; grain growth promoter; grain size; lattice constant; mechanical quality factor; microstructure; perovskite structure; piezoceramics; porosity; segregation; tetragonality; Acceleration; Additives; Ceramics; Chromium; Dielectric losses; Electric resistance; Lattices; Lead; Microstructure; Titanium compounds;
Conference_Titel :
Applications of Ferroelectrics, 1992. ISAF '92., Proceedings of the Eighth IEEE International Symposium on
Conference_Location :
Greenville, SC
Print_ISBN :
0-7803-0465-9
DOI :
10.1109/ISAF.1992.300574
