SINGLE-CRYSTAL PB(ZRXTI1-X)O-3 THIN-FILMS PREPARED BY METAL-ORGANIC CHEMICAL-VAPOR-DEPOSITION - SYSTEMATIC COMPOSITIONAL VARIATION OF ELECTRONIC AND OPTICAL-PROPERTIES
Cm. Foster et al., SINGLE-CRYSTAL PB(ZRXTI1-X)O-3 THIN-FILMS PREPARED BY METAL-ORGANIC CHEMICAL-VAPOR-DEPOSITION - SYSTEMATIC COMPOSITIONAL VARIATION OF ELECTRONIC AND OPTICAL-PROPERTIES, Journal of applied physics, 81(5), 1997, pp. 2349-2357
Single-crystal thin films of Pb(ZrxTi1-x)O-3 (PZT) covering the full c
ompositional range (0 less than or equal to x less than or equal to 1)
were deposited by metal-organic chemical vapor deposition. Epitaxial
SrRuO3(001) thin films grown on SrTiO3(001) substrates by rf-magnetron
sputter deposition served as template electrode layers to promote the
epitaxial growth of PZT. X-ray diffraction, energy-dispersive x-ray s
pectroscopy, atomic force microscopy, transmission electron microscopy
, and optical waveguiding were used to characterize the crystalline st
ructure, composition, surface morphology, microstructure, refractive i
ndex, and film thickness of the deposited films. The PZT films were si
ngle crystalline for all compositions exhibiting cube-on-cube growth e
pitaxy with the substrate and showed very high degrees of crystallinit
y and orientation. The films exhibited typical root mean square surfac
e roughness of similar to 1.0-2.5 nm. For tetragonal films, the surfac
e morphology was dominated by grain tilting resulting from ferroelectr
ic domain formation. We report the systematic compositional variation
of the optical, dielectric, polarization, and electronic transport pro
perties of these single-crystalline PZT thin films. We show that the s
olid-solution phase diagram of the PZT system for thin films differs f
rom the bulk due to epitaxy-induced strains and interfacial defect for
mation. High values of remanant polarization (30-55 mu C/cm(2)) were o
bserved for ferroelectric compositions in the range of 0.8 less than o
r equal to x less than or equal to 0.2. Unlike previous studies, the d
ielectric constant exhibited a clear dependence on composition with va
lues ranging from 225 to 650. The coercive fields decreased with incre
asing Zr concentration to a minimum of 20 kV/cm for x=0.8. The undoped
films exhibited both high resistivity and dielectric-breakdown streng
th (10(13)-10(14) Omega cm at 100 kV/cm and 300-700 kV/cm, respectivel
y). (C) 1997 American Institute of Physics.