PMN-PT Single Crystals Research Articles

Depoling and fatigue behavior of Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystal at megahertz frequencies under bipolar electric field.

Bipolar electric field induced degradation in [001]c poled Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 (PMN-0.29PT) single crystals was investigated at megahertz frequencies. The electromechanical coupling factor kt , dielectric constant εr , dielectric loss D, and piezoelectric constant d33 were measured as a function of amplitude, frequency, and number of cycles of the applied electric field. Our results showed that samples degrade rapidly when the field amplitude is larger than a critical value due to the onset of domain switching. We define this critical value as the effective coercive field Ec at high frequencies, which increases drastically with frequency. We also demonstrate an effective counter-depoling method by using a dc bias, which could help the design of high field driven devices based on PMN-PT single crystals and operated at megahertz frequencies.

Cautions to predicate multiferroic by atomic force microscopy

With the ever-increasing research activities in multiferroic driven by its profound physics and enormous potential for application, magnetic force microscopy (MFM), as a variety of atomic force microscope (AFM), has been brought to investigate the magnetic properties and the voltage controlled magnetism, especially in thin films and heterostructures. Here by taking a representative multiferroic system BiFeO3/La0.67Sr0.33MnO3 heterostructure and a ferroelectric PMN-PT single crystal for examples, we demonstrated that the MFM image is prone to be seriously interfered by the electrostatic interaction between the tip and sample surface, and misleads the predication of multiferroic. Assisted by the scanning Kelvin probe microscopy (SKPM), the origin and mechanism were discussed and an effective solution was proposed.

Photoconductivity and photostimulated currency in PMN-PT

ABSTRACTThe photoconductivity and the photostimulated currency were measured in PMN-PT single crystals. Based on the experimental data, the characteristics of the density of states of the defect levels and the possibility of their participation in the formation of a diffuse phase transition are discussed.

PMN-PT based smart sensing system for viscosity and density measurement

Abstract This paper presents a smart sensing system for viscosity and density measurement of viscous fluids. The proposed system is based on the vibrational properties of a cantilever probe bonded with newly developed piezoelectric materials–Lead Magnesium Niobate/Lead Titanate (PMN-PT) transducer, which has a piezoelectric charge constant (d33) more than 3 times larger than that of traditional piezoelectric material Lead zirconate titanate (PZT). The proposed system utilizes a PMN-PT single crystal for actuation and laser vibrometer for vibration detection. Using the PMN-PT transducer, the measured viscosity and density of fluids were extracted by analyzing the vibrational properties of the smart probe. Finite element analysis was conducted with COMSOL Multiphysics for theoretical calculation and lab tests were carried out to verify and evaluate the simulation results. This smart sensing system can be applied to in-field, in situ and real-time monitoring of viscous fluids, such as blood, engine oil and early-age concrete.

Investigation of piezoelectric property and nanodomain structures for PIN–PZ–PMN–PT single crystals as a function of crystallographic orientation and temperature

The anisotropy of nanodomain structures and the domain switching in the Pb(In1/2Nb1/2)O3–PbZrO3–Pb(Mg1/3Nb2/3)O3–PbTiO3 system were investigated systematically.

Electron microscopic analysis of surface damaged layer in Pb(Mg1/3Nb2/3)O3–PbTiO3 single crystal

Single crystals of lead magnesium niobate–lead titanate, Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN–PT), have superior dielectric and piezoelectric properties suitable for medical ultrasound imaging. Imaging devices with superior performance can be manufactured from thinner PMN–PT single crystals by mechanical dicing and/or polishing. Although it is often a concern that a damaged layer may form during the mechanical dicing and/or thinning process, the microscopic characteristics of the damaged layer have not yet been investigated in detail. In this study, the microstructural characterization of a damaged layer was investigated by transmission electron microscopy. It was found that mechanical polishing introduced dislocation near the surface of the crystal. It was also found that the domain structure was affected by the introduction of dislocation.

PMN-PT single crystal for endoscopic ultrasound 2D array application

Based on lead magnesium niobate-lead titanate single crystal, a 24 × 24 row-column addressing endoscopic two-dimensional array has been successfully fabricated using novel flanged electrodes and “semi-kerf” technologies. Each row/column array element was measured to have an electromechanical coupling coefficient of 0.81, a center frequency of 5MHz, and a fractional bandwidth of approximately 88% at −6 dB. Of particular significance was that the lead magnesium niobate-lead titanate element exhibits much higher sensitivity compared with lead zirconate titanate-based 2D arrays with similar operational frequency and element area. According to the Field II simulated results, although the obtained beamwidth at −6 dB was a little inferior to that of the fully sampled 24 × 24 two-dimensional array, it is believed that the beamwidth can be improved by appropriately increasing the element number. These results demonstrated that the lead magnesium niobate-lead titanate single-crystal 2D array is a promising candidate for real-time three-dimensional endoscopic ultrasound imaging.

Piezoelectric 3D actuator for micro-manipulation based on [011]-poled PMN-PT single crystal

This paper sets forth to study and demonstrate the usability of an emerging piezoelectric material, called Lead Magnesium Niobate–Lead Titanate (PMN–PT), as a potential actuator for dexterous micro-manipulation. For this purpose, a generic structure called a duobimorph cantilever is studied. The proposed design takes advantage of a specific transverse elongation property of the PMN-PT poled in the [011] crystalline direction. A static 3D analytical model is presented, that links the applied voltage signals to the displacement and blocking force along each axis. Experimental characterization is conducted on 21.0×0.6×0.41mm3 cantilevers to validate the analytical 3D model. The transverse and longitudinal displacement range (not counting end-effectors) is over 460μm and 40μm respectively, while still generating high forces typically in the range of 16.5–48.2mN, values which are significantly higher than in the case of regular Lead Zirconate Titanate (PZT) ceramics. Results also show that PMN-PT has a good linearity, i.e. a very low hysteresis in the range of 2.8–6%, which is around 5 times lower than in the case of PZT. Next, in order to test the potential of this material for micro-manipulation devices, a pair of duobimorph cantilevers is used to build a microgripper. This device is used to conduct a 3D pick-and-place exercise without assistance from external motorized stages. A number of six useful Degrees of Freedom (DoF) are thus achieved, which is a novelty for cantilevered piezoelectric grippers. The results prove that PMN-PT is a great candidate for precise motion generation while still generating large displacement, which is a key factor for any Micro Electro Mechanical Systems (MEMS) implementation. Furthermore, PMN-PT of [011] type particularly can be used in complex, yet more compact, multi-DoF micro-manipulation applications.

Contribution to the large and stable electric field induced strain for textured Pb(Mg1/3Nb2/3)0.675Ti0.325O3 ceramics

Textured Pb(Mg1/3Nb2/3)0.675Ti0.325O3 (PMN-PT) ceramics were prepared by the templated grain growth method with 3% plate-like BaTiO3 as templates. The degree of grain orientation was about 81% by calculating from the XRD pattern. Temperature dependence of electric field induced strain was measured for both untextured and textured PMN-PT ceramics. The results show that the electric field induced strain for textured PMN-PT ceramics is much larger and more stable than that for untextured PMN-PT ceramics in a wide temperature range. The contribution from the piezoelectric effect and electrostrictive effect to the strain was analyzed, and it was found that textured PMN-PT ceramics exhibited electrostrictive coefficient Q33 as high as 5.19 × 10−2 m4 C−2 and it was comparable to that of PMN-PT single crystals. The electrostrictive effect contributed the main part of the enhancement of electric field induced strain for textured PMN-PT ceramics.

An anisotropic ultrasonic transducer for Lamb wave applications

An anisotropic ultrasonic transducer is proposed for Lamb wave applications, such as passive damage or impact localization based on ultrasonic guided wave theory. This transducer is made from a PMNPT single crystal, and has different piezoelectric coefficients <TEX>$d_{31}$</TEX> and <TEX>$d_{32}$</TEX>, which are the same for the conventional piezoelectric materials, such as Lead zirconate titanate (PZT). Different piezoelectric coefficients result in directionality of guided wave generated by this transducer, in other words, it is an anisotropic ultrasonic transducer. And thus, it has different sensitivity in comparison with conventional ultrasonic transducer. The anisotropic one can provide more information related to the direction when it is used as sensors. This paper first shows its detailed properties, including analytical formulae and finite elements simulations. Then, its application is described.

Comparison of PZN-PT, PMN-PT single crystals and PZT ceramic for vibration energy harvesting

Vibration energy harvesting has a great potential to achieve self-powered operations for wireless sensors, wearable devices and medical electronics, and thus has attracted much attention in academia and industry. The majority of research into this subject has focused on the piezoelectric effect of synthetic materials, especially the perovskite PZT ceramics. Recently the new-generation piezoelectric materials PMN-PT and PZN-PT single crystals have gained significant interest because of their outstanding piezoelectric properties. They can be used to replace the widely-adopted PZT ceramics for improving energy harvesters’ performance substantially. However, there is little research on comparing PMN-PT and PZN-PT energy harvesters against PZT harvesters. In this paper, we present a systematic comparison between vibration energy harvesters using the PMN-PT, PZN-PT single crystals and those using the PZT ceramics. Key properties of the three materials are summarized and compared. The performance of the PMN-PT and PZN-PT energy harvesters is characterized under different conditions (beam length, resistance, frequency, excitation strength, and backward coupling effect), and is quantitatively compared with the PZT counterpart. Furthermore, the effect of the synchronized switch harvesting on inductor (SSHI) circuit on the three harvesters is discussed. The experimental results indicate that energy harvesters using the PMN-PT and PZN-PT single crystals can significantly outperform those using the PZT ceramics. This study provides a strong base for future research on high-performance energy harvesters using the new PMN-PT and PZN-PT single crystals.

A multisource energy harvesting utilizing highly efficient ferroelectric PMN-PT single crystal

This paper demonstrates a multi-source energy harvester that is able to utilize simultaneously both piezoelectric and pyroelectric effects in lead magnesium niobate-lead titanate (PMN-PT) single crystal. The paper presents a study of PMN-PT single crystal with a (67:33) composition grown in our laboratory via a vertical gradient freeze method without any flux. The performance of the piezoelectric and pyroelectric energy harvester using unimorph device structure was evaluated via modeling and experiment. The theoretical study was implemented based on a distributed parameter electromechanical model and the modelling procedure was approximated using finite element analysis to predict the electromechanical behavior of the harvester. The maximum power density at a resonance frequency of 50 Hz and optimum resistance of 2 MΩ was 16.7 nW/(g2 cm3) under a 1 g acceleration of vibration. The measured values of electrical output parameters were in good agreement with theoretical and modelling results using MATLAB and COMSOL Multiphysics, respectively. By using the pyroelectric effect along with the piezoelectric effect, the output voltage of the energy harvester was found to be enhanced at the optimum resistance and specific frequency values. It was noticed that the output voltage was increased monotonically with temperature-difference (ΔT) and reaches up to 180 % of its original value under temperature difference of 1.7 °C at a frequency value of 49 Hz.

Shear-Mode-Based Cantilever Driving Low-Frequency Piezoelectric Energy Harvester Using 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3.

Energy harvesting from external mechanical excitation has become a hot interest area, and relaxor piezoelectric single crystal ( 1 - x )Pb(Mg1/3Nb2/3)O3- x PbTiO3 (PMN- x PT or PMN-PT) has attracted continuous attention due to the well-known ultrahigh shear-mode electromechanical response. To exploit the low-frequency application of excellent shear-mode performance of the PMN-PT single crystal, we proposed a Shear-mode-based CANtilever Driving Low-frequency Energy harvester. The device is composed of two symmetrically assembled sandwich structures and a cantilever, in which sandwich structures can be driven by the cantilever. An analytical method was used to illustrate the high output mechanism, and a finite-element method model of the device was also established to optimize the generated electric energy in this device. The electrical properties of the device under different excitation frequencies and load resistances were studied systematically. The maximum voltage and power density at resonance frequency (43.8 Hz) were measured to be 60.8 V and 10.8 mW/cm(3) under a proof mass of 13.5 g, respectively. Both theoretical and experimental results demonstrate the considerable potential of the resonance-excited shear-mode energy harvester applied to wireless sensors and low-power portable electronics.

Macroscopic lamellar heterophase pattern inPb(Mg1/3Nb2/3)O3−PbTiO3single crystals

The paper describes heterostructures spontaneously formed in PMN-PT single crystals cooled under bias electric field applied along [001]pc and then zero-field-heated in the vicinity of the so-called depoling temperature. In particular, formation of lamellar structures composed of tetragonal-like and rhombohedral-like layers extending over macroscopic (mm) lengths is demonstrated by optical observations and polarized Raman investigations.

Phase transition and domain configuration of poled rhombohedral PIN–PZ–PMN–PT single crystals

A perovskite single crystal of the quaternary system PIN–PZ–PMN–PT, with rhombohedral (R) symmetry (3m) and a size of 10 × 10 × 6 mm3, was successfully grown by a slow cooling method, which had a high rhombohedral-to-tetragonal (T) ferroelectric (FE) phase transition temperature (TR–T = 129 °C). The introduction of In3+ and Zr4+ enhanced the repulsion intensity between Pb2+ and B-site cations in the ABO3 lattice and increased the energy difference ΔET–R, resulting in an improved FE phase transition temperature compared to the PMN–PT binary system single crystals. The evolution of domain configuration induced by both electric field and temperature was studied for the [001]C PIN–PZ–PMN–PT single crystal by using a polarized light microscope. Star porphyritic domains with short-range order before poling and stripe domains with long-range order after poling were observed, respectively, confirming the typical relaxor domain configurations of the R phase. Fine domain walls induced by temperature for the poled [001]C sample were responsible for the high piezoelectric property. Furthermore, minor ferroelectric property variations (ΔPmax < 6%, ΔPr < 10%) were observed at the temperature range from 20 °C to 140 °C, indicating the good thermal stability of the quaternary system PIN–PZ–PMN–PT single crystal.

Surface topography and dielectric properties of polished PMN-PT single crystals

PMN-PT single crystals were polished to a roughness of 1nm Sa and etched as well as heat-treated. The surface topography and dielectric properties of the samples were measured by various methods. The surface has an uneven structure with the appearance of fingerprints owing to the domain structure of the surface. A domain with positive polarity has a higher removal rate than one with negative polarity. The polishing rate strongly depends on the pH of the polishing fluid. The dielectric constant decreases with decreasing thickness of the polished sample, although such a decrease may be recovered by suitable heat treatment.

Infrared light gated MoS₂ field effect transistor.

Molybdenum disulfide (MoS₂) as a promising 2D material has attracted extensive attentions due to its unique physical, optical and electrical properties. In this work, we demonstrate an infrared (IR) light gated MoS₂ transistor through a device composed of MoS₂ monolayer and a ferroelectric single crystal Pb(Mg(1/3)Nb(2/3))O₃-PbTiO₃ (PMN-PT). With a monolayer MoS₂ onto the top surface of (111) PMN-PT crystal, the drain current of MoS₂ channel can be modulated with infrared illumination and this modulation process is reversible. Thus, the transistor can work as a new kind of IR photodetector with a high IR responsivity of 114%/Wcm⁻². The IR response of MoS₂ transistor is attributed to the polarization change of PMN-PT single crystal induced by the pyroelectric effect which results in a field effect. Our result promises the application of MoS₂ 2D material in infrared optoelectronic devices. Combining with the intrinsic photocurrent feature of MoS₂ in the visible range, the MoS₂ on ferroelectric single crystal may be sensitive to a broadband wavelength of light.

Temperature-dependent phase transition in orthorhombic [0 0 1]c-oriented low In3+ doping 19PIN–45PMN–36PT single crystals

PIN–PMN–PT single crystals near the morphotropic phase boundary with low level of In3+ doping were grown through slow cooling their high temperature solution. Temperature-dependent dielectric constants and pyroelectric coefficients indicated two phase transitions, i.e. orthorhombic (O)–tetragonal (T)–cubic (C), took place in 19PIN–45PMN–36PT single crystals upon heating from 35°C to 250°C. The dielectric constant of O phase was higher than that of T phase, which was related to the polarization rotation. When the temperature approached to the depolarization temperature, tetragonal macrodomains converted to microdomains. The polarization change led to the analogous observed in the plots of temperature-dependent pyroelectric coefficients and dielectric constants. However, the temperature-dependent remanent polarization indicated a lower O–T phase transition temperature. Such a discrepancy in Tot could be ascribed to the decline of ferroelectric phase transition energy caused by the superposition of the AC field at each temperature test point when perform bipolar ferroelectric hysteresis loops measuring. The domain structure variation upon heating an unpoled [001]c-oriented 19PIN–45PMN–36PT single crystal was observed with a polarized light microscopy, further indicating the occurrence of the two phase transitions.

라우에 배면반사법을 이용한 PMN-PT 단결정 성장 방향 분석

In this paper, the growing orientation of PMN-PT single crystal is analyzed using the Laue-Back Reflection Method. Two kinds of PMN-PT single crystals are grown using the Bridgman growing method in the [001] and [111] directions and their the Laue photographs are simulated assuming cubic crystal systems. From the comparison between simulation and test results, it can be concluded that the single crystals are grown in the desired crystal orientations.

Dynamic in situ visualization of voltage-driven magnetic domain evolution in multiferroic heterostructures

Voltage control of magnetism in multiferroic heterostructures provides a promising solution to the excessive heating in spintronic devices. Direct observation of voltage-modulated magnetic domain evolution dynamics is desirable for studying the mechanism of the voltage control of magnetism at mesoscale, but has remained challenging. Here we explored a characterization method for the dynamic in situ evolution of pure voltage modulated magnetic domains in the heterostructures by employing the scanning Kerr microscopy function in the magneto optic Kerr effect system. The local magnetization reorientation of a Ni/PMN-PT heterostructure were characterized under sweeping applied voltage on the PMN-PT single crystal, and the results show that the magnetization rotation angle in the local regions is much greater than that obtained from macroscopic magnetization hysteresis loops.