Crystal structure, electrical properties, and mechanical response of (100)-/(001)-oriented epitaxial Pb(Mg1∕3Nb2∕3)O3–PbTiO3 films grown on (100)cSrRuO3‖(100)SrTiO3 substrates by metal-organic chemical vapor deposition

Abstract

Relaxor-type ferroelectric ͑1−x͒Pb͑Mg 1/3 Nb 2/3 ͒O 3 -xPbTiO 3 ͑PMN-PT͒ films, 2 -3 m in thickness, with a PbTiO 3 content ͑x͒ ranging from 0 to 1 were grown on ͑100͒ c SrRuO 3 ʈ ͑100͒SrTiO 3 substrates at 650°C by metal-organic chemical vapor deposition. The effects the x value had on the crystal structure, dielectric and ferroelectric properties, and mechanical response of these films were systematically investigated. Epitaxial growth having ͑100͒ / ͑001͒ orientation irrespective of x and the constituent phase change with x were ascertained from both x-ray diffraction reciprocal space mapping analysis and Raman spectroscopy. The constituent phase changed from a rhombohedral ͑pseudocubic͒ single phase, a mixture phase of rhombohedral ͑pseudocubic͒ and tetragonal phases, and a tetragonal single phase, with increasing x. The mixed phase region was found to exist at x = 0.40-0.55, which was different from that reported for single crystals ͑x = 0.31-0.35͒. The dependencies of relative dielectric constant and remanent polarization on x showed a similar trend in the case of a PMN-PT sintered body; however, the magnitudes of these values were relatively low. The effective longitudinal piezoelectric coefficient ͑d 33,f ͒ and the transverse coefficient ͑e 31,f ͒ of 100-120 pm/ V and ϳ−11.0 C / m 2 were, respectively, calculated for a film with x = 0.39, which corresponds to a larger x edge for the rhombohedral ͑pseudocubic͒ region following the engineered domain concept proposed for PMN-PT single crystals.

Ferroelectric and dielectric properties of 0.62Pb(Mg1/3Nb2/3)O3–0.38PbTiO3 thin films on La0.6Sr0.4CoO3 buffered Si substrates

“…Formation of such preferred orientations is attributed to co-contribution of the surface energy and lattice-match interface energy. In addition, the characterization data indicates that the films mainly comprise of rhombohedra phase, which is consistent with that reported MPB region at around x values of 0.40-0.55 [21] which was larger than that for bulk materials. The out-of-plane lattice parameters calculated from XRD results are 0.3994 and 0.4017 nm for samples A and B, respectively, which is different from that of bulk ceramics (a = 0.3992, c = 0.4052) [22].…”

Low‐Temperature Processing of High‐Performance 0.74Pb(Mg1/3Nb2/3)O3–0.26PbTiO3 Thin Films on La0.6Sr0.4CoO3‐Buffered Si Substrates for Pyroelectric Arrays Applications

“…These suggest that the nucleation and growth kinetics of the films should be a competition of the surface energy and lattice‐match interface energy. The preparation temperature for the 0.74PMN–0.26PT thin films deposited on the LSCO‐buffered Si substrates by RF magnetron sputtering is lower than the previously reported range of 600°C–850°C for the PMN–PT thin films grown on oxide single‐crystal substrates or metal‐coated Si substrates by the sol–gel method, chemical vapor deposition, and PLD . This significant reduction in the crystallization temperature of the PMN–PT thin films relative to other substrates, is consistent with the effective nucleation of PMN–PT grains over the lattice‐matched LSCO layer.…”

“…Recently, these materials, in thin‐film form, have attracted a lot of attention for microelectromechanical systems that provide significant opportunities for the devices for improved performance and further miniaturization based on silicon technology . Many investigations have been focused on the preparation and piezoelectric properties of (1− x )PMN– x PT thin films with composition around morphotropic phase boundary (MPB) (0.30 < x < 0.35) for actuator and transducer applications . However, the PMN–PT thin films prepared by different approaches are known to be elaborated typically at high temperatures (600°C–850°C), which is higher than that conventionally used in Si process technology (about 550°C).…”

“…Many investigations have been focused on the preparation and piezoelectric properties of (1− x )PMN– x PT thin films with composition around morphotropic phase boundary (MPB) (0.30 < x < 0.35) for actuator and transducer applications . However, the PMN–PT thin films prepared by different approaches are known to be elaborated typically at high temperatures (600°C–850°C), which is higher than that conventionally used in Si process technology (about 550°C). Moreover, the ferroelectric, dielectric, and piezoelectric properties are much lower than those of bulk single crystals, which are attributed to phase purity, substrate constraint, strain, and defects, etc …”

Visualization of dielectric constant-electric field-temperature phase maps for imprinted relaxor ferroelectric thin films

“…9 Because this is rarely done, the influence of the imprint on the dielectric properties and its temperature-dependent stability is not well studied. [10][11][12][13][14][15] In this work, three-dimensional (3D) dielectric maps were visualized in order to investigate the imprint effect on the dielectric response of relaxor FE PMN-PT thin films. This was accomplished by repeatedly measuring e r -E loops with increasing T and then constructing 3D e r -E-T phase maps by integrating the measured dielectric hysteresis loops with respect to T. Based on the constructed dielectric maps, the relationship between structural and dielectric properties in the PMN-PT thin films is discussed in conjunction with disorder inside the films.…”