Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 Research Articles

Domain switching and polarization fatigue in rhombohedral PIN‐PMN‐PT and Mn‐doped PIN‐PMN‐PT single crystals

AbstractDomain switching process under alternating electric field was investigated by in situ polarized light microscopy in [001]‐oriented Pb(In1/2Nb1/2)O3‐Pb(Mg1/3Nb2/3)O3‐PbTiO3 (PIN‐PMN‐PT) and Mn‐doped PIN‐PMN‐PT single crystals. Only one‐step 71° switching was confirmed in pure and Mn‐doped PIN‐PMN‐PT crystals by the formed domain walls, whose projections on the (001) plane are along 45° or 135° with respect to [010] direction. Moreover, polarization and strain loops during cyclic electric field were studied in depth as a function of switching cycles. Polarization fatigue appeared obviously above 1000 bipolar cycles in PIN‐PMN‐PT samples, while Mn‐doped PIN‐PMN‐PT samples exhibited almost fatigue‐free characteristics. By considering the thermodynamic theory, the improved fatigue resistance in Mn‐doped PIN‐PMN‐PT crystals stems from the enhanced energy barrier of domain switching. Mn modification does not affect the domain switching paths, but it can enhance the energy barrier of domain switching, leading to the improved fatigue behaviors. Our results provide a useful insight into the underlying mechanisms between the domain switching process and polarization fatigue for applying high‐performance relaxor‐ferroelectric single crystals.

High rhombohedral to tetragonal phase transition temperature and electromechanical response in Pb(Yb1/2Nb1/2)O3-Pb(Sc1/2Nb1/2)O3-PbTiO3 ferroelectric system near the morphotropic phase boundary

Relaxor-PT crystals, that is, Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) and Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT), have been used in mechanical to electric energy translation devices, such as for high-frequency imaging and underwater detection. However, low temperature usage remains a problem for high temperature applications, which are restricted by rhombohedral to tetragonal phase temperatures (TR-T). In this work, we synthesized a new xPb(Yb1/2Nb1/2)O3-yPb(Sc1/2Nb1/2)O3-0.37PbTiO3 (x = 0.2˜0.45) (xPYN-yPSN-0.37 P T) ternary piezoelectric polycrystalline with high TR-T = 225˜245 °C. For 0.45PYN-0.18PSN-0.37 P T ceramics, the piezoelectric coefficient d33, mechanical coupling factors k33, kp, and kt, and dielectric coefficients εr and TR-T are on the order of 330 pm/V, 68.3%, 54.3%, 49.3%, 930, and 245 °C, respectively. Thermal piezoelectric and ferroelectric behaviors were investigated in 0.45PYN-0.18PSN-0.37 P T polycrystalline, which are good candidates for high temperature piezoelectric application. DSC curves for xPYN-yPSN-0.37 P T systems present two peaks at 1213 and 1291 °C during the cooling process, showing good crystallization behavior and suitability for single crystal growth.

Effect of segregation on Mn-doped relaxor-PT single crystal

The effect of compositional segregation on the properties of relaxor ferroelectric single crystal are attracting increasing attention for its serious limitation on the application field. In this paper, the composition, phase structure, optical properties and electric properties of Mn-doped Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) single crystal were investigated. The real composition of the single crystal fluctuated around the original ratio, except for MnO2. The single crystal contained less Mn element after removing inclusions compared with the starting ratio. The single crystal samples exhibited rhombohedral phase (R phase), orthorhombic phase (O phase) and tetragonal phase (T phase) structures with different composition due to the segregation. The rhombohedral to tetragonal phase transition temperature (TR-T) shifted to a lower value along the growth direction, while the Curie Temperature (TC) shifted to a higher value instead. The relaxation level of the single crystal went down to a lower level when the crystal structure changed from R phase to T and O phase. The coercive field (EC) with [001] poling in R phase remained stable before a rise in O phase and T phase. However, the composition segregation didn't obviously affected the internal bias field and kept around 0.2 kV/cm. The piezoelectric coefficient d33 and unipolar strain with poling direction along [001] had the same trend along growth direction. The curves of them both took a rapid fall at the top of the single crystal boule, which related to the T phase.

Enhanced texture evolution and piezoelectric properties in CuO-doped Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 grain-oriented ceramics

In this work, both crystallographic texture and doping engineering strategies were integrated to develop relaxor-PbTiO3 (PT) based ternary ferroelectric ceramics with enhanced texture evolution and superior electromechanical properties. CuO-doped Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) piezoelectric ceramics with [001]c texture fraction ≥97% were synthesized by templated grain growth. The addition of CuO significantly promotes densification and oriented grain growth in the templated ceramics, leading to full texture development at dramatically reduced times and temperatures. Moreover, the CuO dopant remarkably enhances the piezoelectric properties of the textured ceramics while maintaining high phase transition temperatures and large coercive fields. Doping 0.125 wt. % CuO yields the electromechanical properties of d33 = 927 pC/N, d33* = 1510 pm/V, g33 = 43.2 × 10−3 Vm/N, Kp = 0.87, Ec=8.8 kV/cm, and tan δ = 1.3%, which are the best values reported so far in PIN-PMN-PT based ceramics. The high piezoelectric coefficient is mainly from the reversible piezoelectric response, with the irreversible contribution being on the order of 13.1%. We believe that this work not only facilitates closing the performance gap between ceramics and single crystals but also can expand relaxor-PT based piezoelectric application fields.

High composition uniformity of 4″ of PIN-PMN-PT single crystals grown by the modified Bridgman method

Relaxor based ferroelectric single crystals Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) with composition near morphotropic phase boundary exhibit extraordinary piezoelectric properties. Due to the composition segregation during crystal growth, the composition and properties of PIN-PMN-PT single crystal boules are poor uniformity. In this work, uniformity of dielectric and piezoelectric properties of the crystal boules with 4″ diameter by 100mm long were clearly improved along the crystal growth direction by the modified Bridgman method. For 70% length of the boule, TRT and Tc were around 100°C and 160–180°C along the growth direction, respectively. The variety of piezoelectric constant d33 is about 1500-1800pC/N in the same range of the boule. So that PIN-PMN-PT crystals will be more cost-effective and beneficial for ultrasonic applications in higher temperature region.

111]-oriented PIN-PMN-PT crystals with ultrahigh dielectric permittivity and high frequency constant for high-frequency transducer applications

The electromechanical properties of [111]-oriented tetragonal Pb(In1/2Nb1/2O3)-Pb(Mg1/3Nb2/3O3)-PbTiO3 (PIN-PMN-PT) crystals were investigated for potential high frequency ultrasonic transducers. The domain-engineered tetragonal crystals exhibit an ultrahigh free dielectric permittivity ε33T > 10 000 with a moderate electromechanical coupling factor k33 ∼ 0.79, leading to a high clamped dielectric permittivity ε33S of 2800, significantly higher than those of the rhombohedral relaxor-PT crystals and high-K (dielectric permittivity) piezoelectric ceramics. Of particular significance is that the [111]-oriented tetragonal crystals were found to possess high elastic stiffness, with frequency constant N33 of ∼2400 Hz m, allowing relatively easy fabrication of high-frequency transducers. In addition, no scaling effect of piezoelectric and dielectric properties was observed down to thickness of 0.1 mm, corresponding to an operational frequency of ∼24 MHz. These advantages of [111]-oriented tetragonal PIN-PMN-PT crystals will benefit high-frequency ultrasonic array transducers, allowing for high sensitivity, broad bandwidth, and reduced noise/crosstalk.

Formation mechanism of highly [0 0 1]c textured Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 relaxor ferroelectric ceramics with giant piezoelectricity

We investigated the synthesis mechanism and giant piezoelectricity of highly [001]c textured Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) relaxor based ferroelectric ceramics (texture fraction ∼94%) with BaTiO3 (BT) templates. The onset of texture occurred at ∼88% relative density (RD), and rapid increase in texture fraction happened with RD>94%. A PbO-rich grain boundary liquid of ∼6–13nm thickness, detected at oriented crystalline interfaces, facilitated epitaxial nucleation and subsequent [001]PIN-PMN-PT||[001]BT growth of textured grains on BT templates. Interfaces between BT templates and PIN-PMN-PT textured grains were found to be coherent and defect-free at the atomic scale, and there was almost no barium diffusion across the interfaces during the texturing process. Nanodomains were clearly visible in the oriented grains. [001]c poling ordered the domain structures of textured ceramics and resulted in a more uniform domain size of several hundred nanometers. The textured ternary PIN-PMN-PT ceramics exhibited ∼200% improvement in piezoelectric response relative to their random counterparts, as a result of their piezoelectric anisotropy and engineered domain status along with higher mobility of domain walls.

Simultaneous Stress and Field Control of Sustainable Switching of Ferroelectric Phases.

In ferroelectrics, manifestation of a strong electromechanical coupling is attributed to both engineered domain morphology and phase transformations. However, realization of large sustainable and reversible strains and polarization rotation has been limited by fatigue, nonlinearity and hysteresis losses. Here, we demonstrate that large strain and polarization rotation can be generated for over 40 × 106 cycles with little fatigue by realization of a reversible ferroelectric-ferroelectric phase transition in [011] cut Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) relaxor ferroelectric single crystal. Direct tuning of this effect through combination of stress and applied electric field, confirmed both macroscopically and microscopically with x-ray and Raman scattering, reveals the local symmetry while sweeping through the transition with a low applied electric field (<0.2 MV/m) under mechanical stress. The observed change in local symmetry as determined by x-ray scattering confirms a proposed polarization rotation mechanism corresponding to a transition between rhombohedral and orthorhombic phases. These results shed more light onto the nature of this reversible transformation between two ferroelectric phases and advance towards the development of a wide range of ferroic and multiferroic devices.

Enhanced electromechanical properties and phase transition temperatures in [001] textured Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 ternary ceramics

[001] oriented relaxor based ternary Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) ceramics were fabricated by templated grain growth. The effects of BaTiO3 template amount on the [001] orientation degree, microstructure, and resulting changes in dielectric, piezoelectric, and ferroelectric properties of PIN-PMN-PT were investigated. A high [001] texture fraction of 93% was achieved in the PIN-PMN-PT ceramics at 5 vol. % BaTiO3 template. Giant electromechanical properties (d33* = 1555 pC/N, d33 = 824 pC/N, and kp = 0.81) and high ferroelectric properties (Ec = 8.3 kV/cm and Pr = 31 μC/cm2) were obtained from those highly textured ceramics, which are much superior to those of randomly oriented counterpart. Furthermore, the textured ternary ceramics exhibited remarkably improved phase transition temperatures (Tr-t = 120 °C and Tc = 203 °C) compared with previously reported binary PMN-PT textured ceramics. The domain structure was characterized by piezoelectric force microscopy, and domain contribution to the enhanced piezoelectric response in the textured PIN-PMN-PT ceramics was analyzed. The high-quality textured ternary ceramics are very promising for new-generation electromechanical devices with high performance and wide temperature usage range.

High performance relaxor-based ferroelectric single crystals for ultrasonic transducer applications.

Relaxor-based ferroelectric single crystals Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) have drawn much attention in the ferroelectric field because of their excellent piezoelectric properties and high electromechanical coupling coefficients (d33∼2000 pC/N, kt∼60%) near the morphotropic phase boundary (MPB). Ternary Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) single crystals also possess outstanding performance comparable with PMN-PT single crystals, but have higher phase transition temperatures (rhombohedral to tetragonal Trt, and tetragonal to cubic Tc) and larger coercive field Ec. Therefore, these relaxor-based single crystals have been extensively employed for ultrasonic transducer applications. In this paper, an overview of our work and perspectives on using PMN-PT and PIN-PMN-PT single crystals for ultrasonic transducer applications is presented. Various types of single-element ultrasonic transducers, including endoscopic transducers, intravascular transducers, high-frequency and high-temperature transducers fabricated using the PMN-PT and PIN-PMN-PT crystals and their 2-2 and 1-3 composites are reported. Besides, the fabrication and characterization of the array transducers, such as phased array, cylindrical shaped linear array, high-temperature linear array, radial endoscopic array, and annular array, are also addressed.

In-situ observation of domain wall motion in Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals

Various domain structures, including wave-like domains, mixed needle-like and laminar domains, typical embedded 90° and 180° domains, have been observed in unpoled rhombohedral, monoclinic, and tetragonal Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals by polarizing light microscope; while in poled tetragonal crystals, the parallel 180° domains were reversed and only vertical 90° domain walls were observed. For 0.24PIN-0.42PMN-0.34PT crystals with morphotropic phase boundary composition, the domain wall motion was in-situ observed as a function of applied electric field along crystallographic [100] direction. With increasing the electric field from 0 to 12 kV/cm, the rhombohedral (R) domains were found to change to monoclinic (M) domains and then to tetragonal (T) domains. The electric field-induced phase transition was also confirmed by X-ray diffraction and the temperature-dependent dielectric behavior.

PIN-PMN-PT Single-Crystal-Based 1–3 Piezoelectric Composites for Ultrasonic Transducer Applications

In this work, Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) single crystal/epoxy 1–3 composites with different thicknesses (400 μm to 825 μm) were fabricated using the conventional dice-and-fill method. Their properties were compared with the corresponding lead zirconate titanate (PZT) ceramic 1–3 composites. Excellent properties for ultrasonic transducer applications have been achieved, such as high electromechanical coupling coefficient (kt ≈ 78% to 83%), high piezoelectric strain coefficient (d33 ≈ 1000 pm/V), and lower acoustic impedance (Z ≈ 20 Mrayl). The strain levels of PIN-PMN-PT composites were almost constant (1000 pm/V) with decreasing thickness, being much higher than those of PZT composites (650 pm/V). However, an increase in strain hysteresis was observed with decreasing thickness, reaching 25.3% for the 400-μm single-crystal 1–3 composite, which is lower than the corresponding PZT composites (44.1% for 350-μm PZT ceramic 1–3 composite). These results show that PIN-PMN-PT single-crystal 1–3 composites have great potential for use in advanced ultrasound transducer applications.

Surface Characterisation of a Ferroelectric Single Crystal by Kelvin Probe Force Microscopy

We investigated the surface potential dynamics of a ferroelectric Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIMNT) single crystal using Kelvin probe force microscopy (KPFM). The initial surface potential is a function of the applied bias since it reflects the interplay between the polarisation and screen charges. It is suggested that the different rates of tip injected charges are responsible for the asymmetric behaviour of the initial surface potential dependent on the sign of the applied bias. The polarisation, screen and tip injected charges are considered to explain the difference in surface potential dynamics.

An efficient way to enhance output strain for shear mode Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals: Applying uniaxial stress perpendicular to polar direction

The shear piezoelectric behavior of [001] poled tetragonal and [011] poled rhombohedral Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystals, with “1T” and “2R” domain configurations, respectively, were investigated under uniaxial stress perpendicular to polar direction. The shear piezoelectric coefficient d15 was found to decrease with increasing compressive stress for both “1T” and “2R” crystals. Based on thermodynamic analysis, the phase structure can be stabilized by applying compressive stress perpendicular to polar direction, resulting in a “harder” polarization rotation process, accounts for the reduced shear piezoelectric coefficient. Of particular importance is that the allowable drive electric field was greatly increased and transverse dielectric loss was drastically reduced under compressive stress, leading to the improved maximum-shear-strain.

Phase transition behaviors in relaxor ferroelectric [001]-poled Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystals studied by Brillouin light scattering and dielectric spectroscopies

Phase transition behaviors of [001]-oriented Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) single crystals were studied under unpoled and [001]-poled conditions by Brillouin light scattering and dielectric spectroscopies. The unpoled crystal showed a diffused elastic anomaly accompanied by substantial dielectric dispersion, which were associated with the temperature evolution of polar nanoregions represented by the excitation of strong central peaks. The poled crystal exhibited two-step changes in both dielectric and elastic properties, which were attributed to the successive phase transitions from rhombohedral to tetragonal, and then from tetragonal to cubic phase upon heating. The high-temperature tetragonal-cubic phase transition remained diffused with dielectric dispersion due to local random fields inherent in relaxors. The transverse acoustic mode disappeared at the rhombohedral-tetragonal phase transition indicating a clear symmetry change.

Piezoelectric 36-shear mode for [011] poled 24%Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 ferroelectric crystal

Superior piezoelectric 36-shear mode of [011] poled Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) in zxt+/−45o cut direction is the first practical piezoelectric 36-shear mode reported [P. Han, “Piezoelectric crystal elements of shear mode and process for preparation,” U.S. patent 7,908,722 B2 (2004)]. The investigation on the piezoelectric 36-shear mode of PIN-PMN-PT crystal was carried out and summarized in this paper. The [011] poled 24%Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) crystal was chosen for the study owing to its large coercive electrical field and high de-poling temperature. Following an introduction to the concept of the piezoelectric 36-shear mode and targeting to explore the maximum d36, we have performed the theoretical calculation on d36 by coordinate transformation of a third rank tensor. To verify the results of the calculation, the d36 was measured by two ways: strain measurements (piezoelectric converse effect) and charge measurements (piezoelectric direct effect) on the same composition crystal. It has been distinguished and determined that the maximum d36 piezoelectric coefficients occurred in the zxt + 45o cut direction for negative and in the zxt−45o cut direction for positive, respectively. The electromechanical coupling factor k36 was also studied. The occurrence of the maximum d36 up to 2400 pC/N and the large electromechanical coupling factor k36 as high as 87.8% were theoretically and experimentally confirmed on zxt ± 45o cut, [011] poled 24%PIN-PMN-PT piezoelectric crystals. The 36-shear mode PIN-PMN-PT crystal enables the piezoelectric performance under high electrical field driving.

Pyroelectric performances of relaxor‐based ferroelectric single crystals and related infrared detectors

AbstractWe report in this paper our discovery of remarkably excellent pyroelectric performances in the widely investigated, but still not well understood, relaxor‐based ferroelectric single‐crystalline materials of the solid solution system of Pb(B1, B2)O3 (B1: Mg2+, In3+…, B2: Nb5+, Ta5+…) and PbTiO3, which have already been considered as next‐generation piezoelectric materials with superhigh piezoelectric effect. Values of pyroelectric coefficient as high as 17.2 × 10−4 C/m2 K and of figure of merit for detectivity of 40.2 × 10−5 Pa−1/2 can be produced in the poled crystals specifically in the crystallographic direction along the spontaneous polarization, i.e., the &lt;111&gt; direction in the rhombohedral phase. They show great potential as novel pyroelectric materials for wide applications in infrared (IR) detectors and thermal imagers. Commercialized IR detector prototypes have also been fabricated with the specific detectivity of 1.07 × 109 cm Hz1/2 W−1, which nearly doubles that of conventional LiTaO3 single‐crystal‐based commercialized IR detectors with similar detection mode. The relations among crystal composition, iron doping, orientation, phase structure, domain configuration, and pyroelectric property, as well as between thermal parameters and dielectric properties will also be presented here. They address the physics behind and the IR‐sensor application using the strong pyroelectric effect of this complicated but promising family of pyroelectric materials. Examples are given for Pb(Mg1/3Nb2/3)O3‐PbTiO3 (PMNT) and ternary Pb(In1/2Nb1/2)O3‐Pb(Mg1/3Nb2/3)O3‐PbTiO3 (PIMNT) systems.