Single-crystal thin films of Pb(ZrxTi1−x)O3 (PZT) covering the full compositional range (0⩽x⩽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 spectroscopy, atomic force microscopy, transmission electron microscopy, and optical waveguiding were used to characterize the crystalline structure, composition, surface morphology, microstructure, refractive index, and film thickness of the deposited films. The PZT films were single crystalline for all compositions exhibiting cube-on-cube growth epitaxy with the substrate and showed very high degrees of crystallinity and orientation. The films exhibited typical root mean square surface roughness of ∼1.0–2.5 nm. For tetragonal films, the surface morphology was dominated by grain tilting resulting from ferroelectric domain formation. We report the systematic compositional variation of the optical, dielectric, polarization, and electronic transport properties of these single-crystalline PZT thin films. We show that the solid-solution phase diagram of the PZT system for thin films differs from the bulk due to epitaxy-induced strains and interfacial defect formation. High values of remanant polarization (30–55 μC/cm2) were observed for ferroelectric compositions in the range of 0.8⩽x⩽0.2. Unlike previous studies, the dielectric constant exhibited a clear dependence on composition with values ranging from 225 to 650. The coercive fields decreased with increasing Zr concentration to a minimum of 20 kV/cm for x=0.8. The undoped films exhibited both high resistivity and dielectric-breakdown strength (1013–1014 Ω cm at 100 kV/cm and 300–700 kV/cm, respectively).
Polycrystalline RuO 2 thin films were grown by metal-organic chemical vapor deposition (MOCVD) on both SiO 2 ͞Si(001) and Pt͞Ti͞SiO 2 ͞Si(001) substrates. Films having a controllable and reproducible structural texture and phase purity were synthesized by carefully controlling deposition parameters. Moderate growth temperatures (ϳ350 ± C) and low growth rates (,30Å͞min) produced highly (110)-textured RuO 2 films. Highly (101)-textured RuO 2 films were favored at slightly lower temperatures (ϳ300 ± C) and much higher growth rates (.30Å͞min). The most conductive RuO 3 films had resistivities of 34 to 40 mV-cm at 25 ± C, an average grain size of 65 6 15 nm, and a surface roughness (rms) of 3 to 10 nm. Both single-phase Ru and mixed Ru͞RuO 2 phase material were also fabricated at low temperatures (,350 ± C) by using lower oxygen flow concentrations (,10%).
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