Search

Observation of stripe domains in PbTiO3 thin films using standard x-ray diffraction analysis at room temperature is discussed. High-quality c-axis oriented thin films of varying thickness, from 6 to 210 unit cells, were grown on buffered NH4–HF etched SrTiO3(001) and Nb:SrTiO3(001) substrates using off-axis radio frequency magnetron sputtering. High-resolution linear Qx scans reveal a superstructure around the specular Bragg peaks, consistent with the presence of ferroelectric stripe domains. For thin samples, the stripe width is found to be proportional to the square root of the film thickness, with random in-plane orientation of domains. For films with a thickness of more than ∼100 unit cells, both monodomain samples and stripe domains were observed. We present evidence for the presence of a threshold depolarization field, above which there is a monotonically decreasing relationship between the domain width and the depolarization field. Furthermore, simulations show that random variations in size of the domains affect the separation of the diffuse scattering peaks from that of the specular reflection. [ABSTRACT FROM AUTHOR]

The crystalline and dielectric properties of sputter deposited PbTiO3 thin films were investigated as a function of the film thickness and growth temperature. The crystalline quality was found to be independent of the film thickness from 2.4 to 200 nm. The capacitance of 0.12 mm2 Pt/PbTiO3/SrRuO3 and Pt/PbTiO3/Nb:SrTiO3 capacitors was found to deviate from the ideal parallel plate capacitance for PbTiO3 films thinner than 10 nm. The decrease in capacitance was consistent with field penetration into the electrodes. The surface Pb content, as determined from x-ray photoelectron spectroscopy, was found to decrease with increasing growth temperature from 700 to 760 °C. However, no change could be observed in the crystalline quality. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we discuss the case for integration of epitaxial (Pb,La)(Zr,Ti)O3 (PLZT) thin films with silicon for electro-optic device applications. PLZT films, approximately 500 nm thick, were grown by on-axis radio frequency magnetron sputtering on CeO2/YSZ-buffered Si(100) substrate with a SrRuO3 electrode layer embedded between CeO2 and PLZT. The structural properties and surface topography of the different oxide layers were examined with X-ray diffraction analysis and atomic force microscopy. The perovskite thin films were predominantly (001)-oriented, with a (002) rocking curve halfwidth of approximately 0.3° and a surface roughness compatible with requirements for application in optical devices. The PLZT cation stoichiometry was assessed from quantitative X-ray photoelectron spectroscopy. These measurements uncovered a substantial depletion of lead in the film surface for layers deposited at substrate temperatures above ~600 °C, whereas the surface concentration of La, Zr and Ti remained virtually unaffected over a wide range of growth temperatures. [Copyright &y& Elsevier]

We report on the fabrication of a novel surface acoustic wave device based on piezoelectric interdigital transducers designed in high quality films of Pb(Zr0.2Ti0.8)O3 grown by RF magnetron sputtering. The approach followed is to replace the conventional metallic interdigital transducers by piezoelectric ones consisting of a series of ferroelectric domains with alternating polarization states. The artificial modification of the ferroelectric domain structure is realized by using an atomic force microscope as a local electric field source. A 1.2 μ m wavelength device has been realized and its transmission properties simulated. [ABSTRACT FROM AUTHOR]

Investigates the ferroelectricity in thin tetragonal single-crystalline perovskite films grown by off-axis magnetron sputtering. Measurement of the ferroelectric properties using electric force and piezoelectric microscopy; Time dependence of the measured signals showing a stable ferroelectric polarization in films.