Title :
Electrical properties of chemically derived (Pb,La)TiO3 thin films
Author :
Schwartz, R.W. ; Tuttle, B.A. ; Doughty, D.H. ; Land, C.E. ; Goodnow, D.C. ; Hernandez, C.L. ; Zender, T.J. ; Martinez, S.L.
Author_Institution :
Sandia Nat. Lab., Albuquerque, NM, USA
Abstract :
Ferroelectric lead lanthanum titanate (PLT) thin films with compositions varying from pure PbTiO3 to PLT 25/100 (0 to 25 mol.% La) were prepared by spin-casting 0.25 M solutions containing metallo-organic precursors of Pb, La and Ti. The as-deposited amorphous films were crystallized into the perovskite structure by heat treatment at temperatures between 450 and 650°C. Dielectric and ferroelectric properties of the thin (410-nm) films were characterized. The dielectric constants of the films varied from ~80 to ~690 for La contents varying from 0 to 25 mol.%, respectively. Dissipation factors varied from ~0.03 to ~0.09 over the same compositional range. Also studied was the temperature dependence of the dielectric properties in order to determine the effects of La content on the Curie point (Tc ). It is as found that Tc decreased with increasing La concentration. Coercive field and remanent polarization also decreased with increased La concentration. Hysteresis loops became slim and more symmetric with increasing La content
Keywords :
crystallisation; dielectric hysteresis; dielectric polarisation; ferroelectric Curie temperature; ferroelectric thin films; heat treatment; lead compounds; permittivity; stoichiometry; (PbLa)TiO3; 410 nm; 450 to 650 degC; Curie point; La contents; PLT; PbTiO3; as-deposited amorphous films; chemically derived (Pb,La)TiO3; coercive field; compositions; crystallisation; dielectric constants; dielectric properties; dissipation factors; ferroelectric properties; ferroelectric thin films; heat treatment; hysteresis loops; metallo-organic precursors; perovskite structure; remanent polarization; spin-casting; temperature dependence; Amorphous materials; Chemicals; Crystallization; Dielectric thin films; Ferroelectric films; Ferroelectric materials; Lanthanum; Lead; Titanium compounds; Transistors;
Conference_Titel :
Applications of Ferroelectrics, 1990., IEEE 7th International Symposium on
Conference_Location :
Urbana-Champaign, IL
Print_ISBN :
0-7803-0190-0
DOI :
10.1109/ISAF.1990.200236
