Polarization in pseudocubic epitaxial relaxed PMN-PT thin films

Abstract

Understanding the relationship between structural characteristics and functional properties of complex relaxor ferroelectric thin films is of high interest for designing materials with high performances. In this work, the structure of epitaxial relaxed pulsed-laser-deposited Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT; x = 25, 33, and 40) thin films on LaNiO3/SrTiO3 substrates is analyzed using a variety of diffraction and spectroscopic techniques. While based on the data obtained from high-resolution x-ray diffraction and scanning transmission electron microscopy analysis, the average structure of the PMN-xPT films is metrically cubic, micro-Raman polarimetry measurements indicate the tetragonal-like ferroelectric phase with marked preference for the polarization perpendicular to the film for all three compositions. The results of the Raman scattering analysis are supported by electromechanical properties of the samples, which clearly show that the films have a locally non-centrosymmetric structure. Furthermore, only a gradual enhancement of the electrical properties from PMN-25PT to PMN-40PT is observed, which is attributed to small tetragonal distortions that are highly similar for all three compositions.

Multifunctionality in Electrically Poled PMN–PT/Ni–Mn–In Multiferroic Heterostructure for Flexible Magnetic Field Sensing and Nonvolatile Memory Applications

“…The effective piezoelectric coefficient ( d 33 ) is evaluated from the slope of amplitude × cos(phase) vs bias voltage plot. The d 33 is calculated as ∼180 pm/V, which agrees with the earlier reported results. , Furthermore, MFM amplitude and frequency micrographs with scan area 5 × 5 μm 2 are used to study the localized magnetic response of FSMA film. The amplitude image in Figure g shows the multidomain magnetic structure of the film, and the frequency contrast in Figure h shows the presence of strong repulsive forces between ferromagnetic domains and the tip.…”

“…16,17 The anomalously large piezoelectric coefficient (d 33 > 2500 pC N −1 ) and electromechanical coupling factor (k 33 > 0.9) are associated with configurations near the morphotropic phase boundary (MPB), which lies at ∼33% PT in bulk single crystals. 18 The ultrahigh piezoelectricity in domain-engineered relaxor ferroelectrics around MPB has been explained using various phenomena, such as electric field persuaded phase transformation, change of polarization via diverse ferroelectric phases near MPB, and versatile domain structure. 19 PMN−PT is optimistic in the plethora of applications, such as energy harvesting, sensing, actuation, information storage, medical ultrasound, and transducers.…”

“…The selection of a piezoelectric material possessing excellent piezoelectricity and ferroelectric properties is crucial to obtaining high-performance ME and MEMS-based devices. Pb­(Mg 1/3 Nb 2/3 )­O 3 –PbTiO 3 (PMN–PT) is a propitious relaxor-based perovskite ferroelectric material as it exhibits fascinating dielectric and piezoelectric characteristics coupled with large remnant polarization and low coercive field. , The anomalously large piezoelectric coefficient ( d 33 > 2500 pC N – 1 ) and electromechanical coupling factor ( k 33 > 0.9) are associated with configurations near the morphotropic phase boundary (MPB), which lies at ∼33% PT in bulk single crystals . The ultrahigh piezoelectricity in domain-engineered relaxor ferroelectrics around MPB has been explained using various phenomena, such as electric field persuaded phase transformation, change of polarization via diverse ferroelectric phases near MPB, and versatile domain structure .…”

Large imprint in epitaxial 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3 thin films for piezoelectric energy harvesting applications

“…6 In thin films, the substrate and the growth mode have a huge effect on the structural characteristics and functional properties of the PMN-PT material. [7][8][9][10] For instance, the piezoelectric coefficients in thin films are an order of magnitude lower relative to bulk PMN-PT single crystals due to substrate clamping. 10 PMN-PT thin films demonstrate slimmer ferroelectric polarization-electric field (P-E) hysteresis loops with low remanent polarization compared to the bulk material, which is beneficial, for instance, for energy storage applications.…”

“…The obtained tetragonality is close to that of the ferroelectric PMN-40PT composition in bulk material. 8 However, for the sample grown on the DSO substrate, the epitaxial strain of the PMN-33PT film is relaxed as a function of the thickness. In this case, the film demonstrates a low tetragonality enhancement (c/a ¼ 1.004) with respect to the bulk.…”