Title :
Ferroelectric transition in the ternary system of Pb(Mg1/3 Nb2/3)O3-La(Mg2/3Nb1/3 )O3-PbTiO3
Author :
Wu, T.B. ; Liu, K.S. ; Chen, J.L.
Author_Institution :
Dept. of Mater. Sci. & Eng., Nat. Tsing Hua Univ., Hsinchu, Taiwan
Abstract :
The ferroelectric transition of ceramics in the ternary system of (1-x-y)Pb(Mg1/3Nb2/3)O3-xLa(Mg2/3 Nb1/3)O3-yPbTiO3 with x=0.05~0.13 and y=0.275~0.575 were investigated by the measurements of X-ray diffraction, dielectric properties and P-E hysteresis. Three morphotropic phases of perovskite structure, i.e. cubic, tetragonal, and rhombohedral, were involved in the study. An increase of PbTiO3 content would cause the structure to evolve to the tetragonal phase; Pb(Mg1/3Nb2/3)O3, to the rhombohedral phase; and, La(Mg2/3Nb2/3)O3 , to the cubic phase. A triple point was found at the composition of x=0.11 and y=0.425. For the composition in the tetragonal phase field, a normal ferroelectric transition and hysteresis characteristic of high coercive field, Ec, over remanent polarization, Pr, were observed. However, for that in the rhombohedral or cubic phase field, a diffuse phase transition and hysteresis characteristic of low Ec over Pr were found. Moreover, the composition at the triple point has shown the a significant diffuse phase transition, and excellent dielectric properties of k≈16000 with high frequency and temperature stability
Keywords :
X-ray diffraction; ceramics; dielectric hysteresis; dielectric polarisation; ferroelectric materials; ferroelectric transitions; lanthanum compounds; lead compounds; permittivity; P-E hysteresis; PMN-LMN-PbTiO3; Pb(Mg13/Nb23/)O3-La(Mg23/Nb 13/)O3-PbTiO3; PbMgO3NbO3-PbMgO3NbO3-PbTiO3; PbTiO3 content; X-ray diffraction; cubic phase; dielectric properties; ferroelectric transition; high coercive field; high frequency; morphotropic phases; perovskite structure; remanent polarization; rhombohedral phase; temperature stability; tetragonal phase; triple point; Ceramics; Dielectric measurements; Ferroelectric materials; Frequency; Hysteresis; Niobium; Polarization; Stability; Temperature; X-ray diffraction;
Conference_Titel :
Applications of Ferroelectrics, 1994.ISAF '94., Proceedings of the Ninth IEEE International Symposium on
Conference_Location :
University Park, PA
Print_ISBN :
0-7803-1847-1
DOI :
10.1109/ISAF.1994.522348
