Title :
An alternative thermodynamic model for PZT
Author :
Bell, Andrew J. ; Furman, Eugene
Author_Institution :
Inst. of Mater. Res., Leeds Univ., UK
fDate :
28 May-1 June 2002
Abstract :
A thermodynamic model is proposed to account for the monoclinic phase observed in the solid solution system Pb(Zr1-xTix)O3. The free energy comprises three sets of terms: two expansions of polarization, one representing each of the end-members, weighted linearly with respect to composition, and terms representing the coupling between the two contributions. Employing previously published coefficients for PbTiO3 and values extrapolated from Zr-rich PZT compositions for PbZrO3, calculations predict the composition of the morphotropic phase boundary between the rhombohedral and tetragonal phases lies at x=0.45 and is virtually independent of temperature and the strength of coupling between the two order parameters. The range of existence of the monoclinic phase depends upon the strength of the coupling, but in general, is broadest at low temperature.
Keywords :
dielectric polarisation; ferroelectric materials; ferroelectric transitions; free energy; lattice constants; lead compounds; piezoelectric materials; polymorphic transformations; PZT; Pb(Zr1-xTix)O3; PbZrO3TiO3; alternative thermodynamic model; end-members; free energy; monoclinic phase; morphotropic phase boundary; order parameters; polarization; rhombohedral-tetragonal phases boundary; strength of coupling; Context modeling; Ferroelectric materials; Lead; Piezoelectric effect; Piezoelectric polarization; Power system modeling; Solid modeling; Temperature dependence; Temperature distribution; Thermodynamics;
Conference_Titel :
Applications of Ferroelectrics, 2002. ISAF 2002. Proceedings of the 13th IEEE International Symposium on
Print_ISBN :
0-7803-7414-2
DOI :
10.1109/ISAF.2002.1195860