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Abstract X-ray diffraction (XRD) reciprocal space mapping (RSM) was used to investigate how nanograted electrodes affect the nanodomain distribution and average crystal structure in near-surface regions of poled Pb(Mg 1/3 Nb 2/3)O 3 -30%PbTiO 3 (PMN-30PT) single crystals. The RSM scans revealed a transverse broadening along the (H00) direction, which was quite different from that of either the rhombohedral (R) or monoclinic A (M A) phase. This broadening provides evidence of a non-uniform distribution of tilt angles between neighboring nanodomains, induced by a gradient in the applied electric field (E). Investigations of the front and back surfaces of the crystals revealed significant differences in the RSM scans. Gradients in the domain distribution and apparent symmetry may extend throughout the crystal thickness. The data evidence changes in the nanodomain distribution that results in adaptations of the average symmetry. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]

The domain structure formation in the congruent lithium tantalate single crystals after IR laser irradiation by linear scanning of Z + polar surface has been studied. Two types of domain structures have been revealed experimentally: self-similar structure and quasi-regular stripe structure. The statistical processing has shown that the increase in the scanning velocity leads to increase in the area with stripe domain structure and to decrease in the average domain period. At the maximum scanning velocity 4.8 m/s, the quasi regular domain stripe structure with average period 0.8 μm has been obtained over the 70% of the switched area. [ABSTRACT FROM AUTHOR]

The domain structure, dielectric, and piezoelectric properties of 0.7 Pb(Mg 1/3 Nb 2/3 )O 3 -0.3PbTiO 3 (PMN-PT) single crystals with nanocomposite electrode, which includes MnO x semiconductor nanogratings and a Ti/Au conductive layer, were studied in this paper. These artificial MnO x nanogratings can alter the electric field distribution and then enhance the domain density. PMN-PT crystals with Ti/Au-MnO x nanocomposite electrodes showed high piezoelectric constant of 2250 p.m./V and dielectric constant of 5400 at 1 kHz, respectively. Compared to ones with conventional planar electrodes, the piezoelectric and dielectric constants of the samples with nanocomposite electrodes were increased 36.7% and 38.3%, respectively. Piezoresponse force microscopy (PFM) images revealed the domain pattern near the electrode/single crystal interface. A linear domain structure induced by the MnO x nanocomposite electrode was found in the samples with thickness less than 200 μm. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) results showed the diffusion of Mn about 300 nm in depth in PMNPT crystal after heat treatment during MnO x nanocomposite electrode. It is believed that the localized high electric fields induced by fringe effects caused by the nanocomposite electrode can enhance nucleation of new domains, and that diffusion from the patterned Mn layer may also lead to an enhancement in domain wall mobility. Our findings open up a new domain engineering technique for tailoring the dielectric and piezoelectric properties of PMN-PT single crystals. [ABSTRACT FROM AUTHOR]

At room temperature, 0.46PIN-0.23PMN-0.33PT single crystals with compositions near the morphotropic phase boundary (MPB) can be induced ferroelectric phase transition by applying an electric field along the direction of [001]c, and the phase change can also explain the origin of the excellent piezoelectric properties of the relaxation ferroelectric single crystal. In the phase boundary components, relaxation properties of single crystal and possible phase structure cause the structure of heterogeneity and uncertainty, and in the process of domain engineering, domain induced polarization rotation and the metastable phase, such as photograph, monoclinic which play an important role on the characteristics of piezoelectric materials. Firstly, the local lattice structure and phase transitions of unpoled 0.24PIN-0.43PMN-0.33PT single crystal were studied by Micro-Raman spectroscopy at room temperature. A total of 11 Raman active modes were ascertained using the Gauss line shape approximation, which deduces that 0.43PIN- 0.26PMN-0.33PT single crystal with morph tropic phase boundary (MPB) composition has monoclinic symmetry. Then MB-MC monoclinic phase transition induced by electric field was studied, from the point of view of energy, the Mc monoclinic phase structure is more stable than MB monoclinic phase structure. [ABSTRACT FROM AUTHOR]

Formation of nanodomain structures during cooling after pulse heating by infrared laser has been studied in congruent lithium tantalate (CLT) and lithium niobate (CLN) single crystals.In situstudy of the domain structure evolution allowed to reveal that in CLN the isolated domains appeared at the edges of the irradiated zone and grew to the center. In contrast, the quasi-regular stripe domain structure appeared in CLT near the edge of irradiated zone. The difference has been attributed to lower Curie temperature and larger pyroelectric coefficient of CLT. The self-organized domain structures can be used for periodical poling with submicron periods. [ABSTRACT FROM AUTHOR]

Two main explanations exist for the deformation mechanisms in Ti–Nb-based gum metals, i.e. the formation of reversible nanodisturbance and reversible stress-induced martensitic transformation. In this work, we used the in situ synchrotron-based high-energy X-ray diffuse-scattering technique to reveal the existence of a specific deformation mechanism, i.e. deformation-induced spatially confined martensitic transformations, in Ti–24Nb–4Zr–8Sn–0.10O single crystals with cubic β parent phase, which explains well some anomalous mechanical properties of the alloy such as low elastic modulus and nonlinear superelasticity. Two kinds of nanosized martensites with different crystal structures were found during uniaxial tensile loading along the [1 1 0] β axis at room temperature and 190 K, respectively. The detailed changes in the martensitic phase transformation characteristics and the transformation kinetics were experimentally observed at different temperatures. The domain switch from non-modulated martensite to a modulated one occurred at 190 K, with its physical origin attributed to the heterogeneity of local phonon softening depending on temperature and inhomogeneous composition in the parent phase. An in-depth understanding of the formation of stress-induced spatially confined nanosized martensites with a large gradient in chemical composition may benefit designs of high-strength and high-ductility alloys. [ABSTRACT FROM AUTHOR]

High-resolution domain studies have been performed in 91PZN-9PT single crystals by piezoresponse force microscopy. Nanometer- and micron-sized strip-shaped 180º and parallel 90º domains were observed in the rhombohedral (R) and tetragonal (T) phases. Domain patterns with the typical sizes 5–200 nm were observed on the (001)cubsurface of unpoled sample. The existence of nanodomains in the sample is tentatively attributed to the relaxor nature of PZN-PT where small polar clusters may form under zero-field cooling conditions. The domain observation confirms the structure of the morphotropic 91PZN-9PT crystals, which is composed of both the R and T (or monoclinic) orientations states. The outstanding piezoelectric properties may result from the cooperative response of the microscale/nanoscale domain structure. [ABSTRACT FROM AUTHOR]

The recent achievements in domain nanotechnology in single crystals of lithium niobate and lithium tantalate family have been reviewed. The formation of nanoscale domain structures has been studied with high spatial resolution using modern experimental methods of domain visualization. Criteria of the investigated ferroelectric material selection and recent experimental achievements have been presented. The physical basis of the nanodomain engineering based on the role of nanoscale domains in formation of the domain patterns in highly non-equilibrium switching conditions has been discussed. The obtained knowledge allows us to manufacture the highly efficient periodically poled crystals for laser light frequency conversion. [ABSTRACT FROM AUTHOR]

The influence of the artificial surface layer (photoresist film) on the domain kinetics was studied in congruent lithium niobate single crystals. The switching current data was fitted by modified Kolmogorov-Avrami formula. The qualitative change of the domain structure evolution for photoresist film thickness above 2 μm was revealed byin situoptical visualization and analysis of the switching current data. The linear dependence of the threshold field increase on the film thickness was found. The quasi-regular nanodomain structures on Z+ polar surface were studied by scanning probe and Raman confocal microscopy and the domain evolution scenario was revealed. [ABSTRACT FROM AUTHOR]

The polarization reversal has been studied by domain structure visualization and switching current recording in LiNbO3single crystals doped by 5% MgO irradiated by Ar+ions. The abnormal domain structure evolution representing formation of charged domain walls has been revealed. It has been shown that low energy ion irradiation leads to increase of the bulk conductivity due to oxygen out-diffusion induced by radiative heating in vacuum. The inhomogeneous distribution of the electric field terminated the polarization reversal in high conductive layer. The analysis of the switching current data allowed revealing the input of the conductive current through charged domain walls. [ABSTRACT FROM AUTHOR]