Title :
Investigation of ferroelectric and pyroelectric properties of ceramics with composition Ba(Li2xAl2-2x)O4-4x F4x (0⩽x⩽0.03)
Author :
Huang, Sui-Yang ; Von Der Mühll, R. ; Ravez, J. ; Hagenmuller, P.
Author_Institution :
Lab. de Chimie du Solide, CNRS, Talence, France
fDate :
30 Aug-2 Sep 1992
Abstract :
The structural, ferroelectric, pyroelectric, and dielectric relaxation properties of ceramics with composition Ba(Li2xAl 2-2x)O (0⩽x⩽0.3) have been investigated. XRD (X-ray diffraction) patterns show a lattice close to that of BaAl2 O4. The parameters increase with increasing x up to x=0.1 and then remain constant. The Curie temperature TC decreases regularly from TC=396 K (x=0) down to TC=324 K (x=0.1) and then increases again with x up to TC=460 K (x=0.3). The values of the spontaneous polarization Ps are in the range 1-22 nC-cm-2. The solid solutions seem to be of weak ferroelectric type with a maximum of Ps around 200 K and low values of ∈´r, the pyroelectric coefficient, and Ps. Dielectric relaxation is detected for Ba(Li0.4Al1.6)O3.2F0.8 with a relaxation frequency from 102 to 104 Hz between 300 and 520 K. A model accounting for weak ferroelectricity is proposed
Keywords :
X-ray diffraction examination of materials; barium compounds; dielectric polarisation; dielectric relaxation; ferroelectric Curie temperature; ferroelectric materials; lattice constants; lithium compounds; pyroelectricity; Curie temperature; X-ray diffraction patterns; ceramics; composition Ba(Li2xAl2-2x)O4-4xF 4x; dielectric relaxation properties; ferroelectric properties; lattice; model; pyroelectric coefficient; pyroelectric properties; relaxation frequency; solid solutions; spontaneous polarization; weak ferroelectricity; Ceramics; Dielectrics; Ferroelectric materials; Lattices; Polarization; Pyroelectricity; Solids; Temperature; X-ray diffraction; X-ray scattering;
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.1992.300641
