PMN-PT Single Crystals Research Articles

Achieving high piezoelectric performance in Pb(Mg1/3Nb2/3)O3–PbTiO3 ferroelectric single crystals through pulse poling technique

To maximize the piezoelectric performance of Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN–PT) single crystals, a pulse poling (PP) method is proposed in this study. This study investigates the effects of pulse poling on the piezoelectric and dielectric properties of these PMN–PT single crystals and explores the polarization rotation mechanisms. Our findings indicate a significant improvement in the piezoelectric properties postpulse poling. The optimal PP conditions are identified as 30 pulse numbers at a pulsed electric field of 5 kV/cm. The dielectric constant ɛT33/ɛ0 and piezoelectric coefficient d33 of PMN–0.28PT post PP are 7000–7700 and 2200–2530 pC/N, respectively, representing increases of 49% and 66% compared with those of postdirect current poling (DCP). Additionally, the domain structures of the PMN–0.28PT single crystals after various DCP and PP treatments are examined and compared using piezoelectric force microscopy. The enhanced piezoelectric properties are attributed to the finer domain structures, as well as increased domain wall density achieved through PP. This research introduces a novel domain engineering approach to improve the electromechanical properties of relaxor ferroelectric single crystals.

Simulation and Fabrication of PMN-PT Single Crystals Phased Array Ultrasonic Transducer Based on Alternating and Direct Current Poling

Simulation and Fabrication of PMN-PT Single Crystals Phased Array Ultrasonic Transducer Based on Alternating and Direct Current Poling

High second-order nonlinearity in single-domain tetragonal PMN-PT single crystal

Recently, Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT) single crystals present tremendous potential in optical applications such as Q-switches and invisible robotic devices because they possess high electro-optic properties and perfect transparency simultaneously. However, due to the difficulties in testing and sample preparation, the nonlinear optical properties of PMN-PT single crystals have not been reported yet, which poses a bottleneck for exploring its nonlinear application. In this work, a large second-order nonlinear coefficient (d31 ∼ 77.9 pm V−1) of single domain PMN-0.39PT single crystal has been revealed, which is times times higher than the maximum nonlinear coefficient of commercial LiNbO3 single crystal (d33 = 25.4 pm V−1). The complete set of nonlinear coefficients of the sample has been determined by second harmonic generation microscopy. This work presents the promising nonlinear optical property in PMN-PT single crystals and opens a door for designing high-performance nonlinear optical devices.

Investigations of high-Performance Ultrasonic Transducers based on PMN-PT Single Crystals

Ultrasonic transducers for NDE applications are commonly based on Lead Zirconate Titanate or PZT, an inorganic compound and ceramic perovskite material. Until now the advantages of PMN-PT are used in medical applications, but are not implemented in NDE. Lead Magnesium Niobate-Lead Titanate (PMN-PT) is well known for its high sensitivity and broad frequency spectrum. While conventional PZT materials have an electromechanical coupling factor K33 (a measure of the conversion between electrical and acoustic energy) of about 0.72, PMN-PT materials reach peak values of more than 0.93. For applications with low signal amplitudes, high electronic noise and small transducer elements, the performance of ultrasonic probes can be significantly enhanced by using Lead Magnesium Niobate-Lead Titanate (PMN-PT) instead of PZT. This single-crystal material offers significantly better piezo parameters and leads to a higher sensitivity and larger bandwidth. There is a better depth resolution possible with this transducers as practical tests have shown. Similar to PZT it can also be fabricated in 1-3 piezo- composite technology. In a cooperation between Fraunhofer IKTS, iBULe Photonics, and IFU Diagnostic Systems, PMN-PT ultrasonic transducers are developed and optimized. The performance of phased array probes and single element transducers was measured by a so called PCUS® pro electronic front end from Fraunhofer and compared with equivalent PZT-based probes. As a result various single element and phased array transducers with im-proved performances are available for NDT of typical aerospace materials and applications. These test setups were used to weigh up the advantages and disadvantages, such as achievable precision or costs, for the implementation of a PMN-PT-based UT matrix probe. Based on this, a wiring variant adapted to the PMN-PT was developed and optimised for the matrix setups by pre- assembling the matching layers. The most favourable setup turned out to be bonding the PMN- PT composites to the prefabricated matching layers together with a rigid-flexible PCB frame. This enabled direct wire bonding of 64 matrix elements to the matching PCB pads on the rigid frame.

Design of PMN-PT-based dual-resonance acoustic emission sensor for partial discharge detection

This paper presents the design, fabrication, and testing of a dual-resonance acoustic emission (AE) sensor based on PMN-PT single crystal for partial discharge (PD) detection. The use of high-performance PMN-PT single crystal enhances the sensor sensitivity. Resonance peak coupling is utilized to increase the bandwidth of the sensor effectively. The effects of piezoelectric vibrator size, vibrator spacing, and external circuitry on the sensor output are analyzed using equivalent circuits and finite element models (FEM) for sensor design. After calibration, the self-made sensor has a peak sensitivity of 76.4 dB and a bandwidth of 20 kHz to 150 kHz, which meets the demand of PD detection. The PD detection experiments verify that the self-made sensors can accurately detect PD with a high signal-to-noise ratio of 15.8 dB. In the end, the reliability test proves that the sensors have good stability and temperature characteristics. Besides above sensor’s performance improvement, our design has the great potential to reduce the sensor’s cross section, resulting better suitability on curved surfaces. The feasibility of employing PMN-PT as a replacement for PZT in the fabrication of AE sensors is proven by these good test results.

Enhanced piezoelectric and optical properties of tetragonal Sm‐doped Pb(In1/2Nb1/2)–Pb(Mg1/3Nb2/3)–PbTiO3 crystals

AbstractRelaxor ferroelectric single crystal Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIN–PMN–PT) has received extensive research and attention due to its excellent piezoelectric, electromechanical, and other properties. In particular, tetragonal relaxor ferroelectric single crystals have shown greater application potential in high‐temperature devices due to their higher Curie temperature and better stability. However, the low piezoelectric performance of tetragonal crystals also greatly limits its application, and research on its optical properties is not sufficient. In this paper, the tetragonal phase Sm–PIN–PMN–PT single crystal was obtained by the Bridgman method, and its piezoelectric and electro‐optical properties are studied. At the same time, we gave a complete set of piezoelectric, dielectric, and elastic coefficient matrices. The results show that the crystal has excellent piezoelectric and electromechanical properties. The piezoelectric coefficient can reach 905pC/N, the electromechanical coupling coefficient k33 is 85%, and the kt is 72%. The transmittance of the sample polarized along [001] direction can reach 66%. The effective electro‐optical coefficient γc is 60 pm/V at room temperature and can reach 86 pm/V at 70°C. It has a wide operating temperature range and stable performance with frequency variation, which has certain reference significance for application in new electro‐optical devices.

Achieving combinatory “soft” and “hard” piezoelectric properties in textured ceramics via exploring single‐crystal‐like electrostriction

AbstractDesign of a projecting‐receiving dual‐purpose transducer is challenging due to the difficulty of synthesizing piezoelectric materials with combinatory “soft” properties (high piezoelectric coefficient d) and “hard” properties (low dielectric loss and high mechanical quality factor Qm). In this study, we provide a different perspective to address this challenge via exploiting single‐crystal‐like electrostriction coefficient Q33 through the fabrication of grain oriented or textured “hard” piezoelectric ceramics. Mn‐doped 0.27Pb(In1/2Nb1/2)O3–0.41Pb(Mg1/3Nb2/3)O3–0.32PbTiO3 (Mn:PIN–PMN–PT) piezoelectric ceramics with a high [0 0 1]c texture fraction of 99% were synthesized, which exhibit three times greater piezoelectric properties (d33 ∼ 828 pC/N) than random counterparts (d33 ∼ 251 pC/N), while maintaining low loss (tan δ ∼ 0.5%, Qm = 443). According to the formula , the large improvement of d33 in textured ceramics is mainly due to a doubling increase in dielectric constant ε33 and Q33 (∼0.057 m4/C2). Notably, the Q33 exhibits remarkable similarity to that of PMN–PT single crystals, further contributing to the enhanced piezoelectric performance of textured ceramics. Phase field model of ferroelectrics was performed to understand the texturing on Q33 and elucidate the underlying mechanism at the domain level. The textured ceramics exhibit excellent combinatory “soft” and “hard” properties, which are the promising materials for developing projecting‐receiving dual‐purpose transducers with high efficiency and high sensitivity.

Design and analysis of a d15 mode piezoelectric energy generator using friction-induced vibration

Research works have been conducted on transverse and longitudinal mode piezoelectric energy generation to collect energy from ambient vibrations. However, the inconsistency with the frequency of the energy source and low output power density remain problems for high energy output. In this work, we propose a shear mode piezoelectric energy generator, which utilizes the friction-induced vibration (FIV) and high shear mode piezoelectric coefficient to improve the energy output. A piezoelectric coupled FIV mathematical model is developed to accurately calculate the dynamic vibration response and voltage output. The dynamic voltage response is validated by experiment, and it proves the possibility of continuous friction-induced high-frequency vibration. The energy generation process is evaluated by transient charging simulation of a storage capacitor through an iteration process, which was experimentally validated in the literature. Parameter studies have been conducted to investigate the influences of the piezoelectric patch dimensional parameters, vibration system parameters, friction model parameters, methods of electrical connections, and different piezoelectric materials on the energy generation performance to provide guidance for better design. Under ideal experiment conditions with proper parameters, a volume of m3 PZT4 piezoelectric material indicates root mean square (RMS) charging power density of Wm−3 and Wm−3 with electrically in parallel and electrically in series, respectively. While using the same amount of material and structural setup, the single crystal PMN-PT piezoelectric material shows RMS charging power density of Wm−3 and Wm−3 with electrically in parallel and electrically in series, correspondingly. These promising results demonstrate that close to W-level RMS charging power output may be realized by structure optimization of energy generator design and incorporating multiple generators together for operation. Possible incorporation into vehicle braking systems can be considered to utilize the wasted friction energy, and it may offer an energy supply for low-power wireless devices.

Orientation-tunable ferroelectric and energy storage properties in PMN–PT single crystals

The ferroelectric and energy storage properties of PMN–PT single crystals with excellent antifatigue performance are improved by controlling their crystal orientations.

Determining AC polarization conditions of ferroelectric materials by dynamic scaling method

Alternating current (AC) polarization can significantly improve electrical and optical performance of ferroelectrics, but there is still no theoretical guidance on how to get the best AC polarization conditions. In this paper, dynamic scaling method is firstly used to the determine optimal AC polarization process, and high piezoelectric coefficients were obtained at a low electric field and a very short time. Results indicate that it is effective not only for Pb-based PMN-PT ceramics, single crystal and PZT ceramics, but also for lead-free BNT-BT ceramics. The dynamic scaling method is expected to provide great support for AC polarization for ferroelectric materials.

Competition between Ferroelectric and Ferroelastic Domain Wall Dynamics during Local Switching in Rhombohedral PMN-PT Single Crystals.

The possibility to control the charge, type, and density of domain walls allows properties of ferroelectric materials to be selectively enhanced or reduced. In ferroelectric-ferroelastic materials, two types of domain walls are possible: pure ferroelectric and ferroelastic-ferroelectric. In this paper, we demonstrated a strategy to control the selective ferroelectric or ferroelastic domain wall formation in the (111) single-domain rhombohedral PMN-PT single crystals at the nanoscale by varying the relative humidity level in a scanning probe microscopy chamber. The solution of the corresponding coupled electro-mechanical boundary problem allows explaining observed competition between ferroelastic and ferroelectric domain growth. The reduction in the ferroelastic domain density during local switching at elevated humidity has been attributed to changes in the electric field spatial distribution and screening effectiveness. The established mechanism is important because it reveals a kinetic nature of the final domain patterns in multiaxial materials and thus provides a general pathway to create desirable domain structure in ferroelectric materials for applications in piezoelectric and optical devices.

Electrical and optical properties of Nd3+-doped rhombohedral Pb(Mg1/3Nb2/3)O3–PbTiO3 ferroelectric single crystal

Lead Magnesium Niobate Titanate 0.74 Pb(Mg1/3Nb2/3)O3-0.26PbTiO3 (0.74PMN-0.26 PT) single crystal doped with 1 mol% Nd3+ was grown by a modified Bridgman approach. Powder X-ray diffraction exhibited perovskite structure containing rhombohedral phase. The dielectric constants of various orientations with temperature were determined. We observed that the polarization process increases the crystal optical performances. The transmittance is significantly increased after poled along [011] direction. Optical properties changes were interpreted by electric domain structure. Energy band gaps were obtained by Tauc equation. Nd3+ has a strong emission transition band near 1062 nm; the long radiation lifetime of 148 μs indicates a low quenching effect. For the Nd-doped PMN-PT single crystals, their optical and electrical performances have been explored to extend the applications in medical, military and practical industrial production.

Increasing Performances of 1–3 Piezocomposite Ultrasonic Transducer by Alternating Current Poling Method

Ultrasonic transducers are the basic core component of diagnostic imaging devices, wherein the piezoelectric materials are the active element of transducers. Recent studies showed that the alternating current poling (ACP) method could develop the properties of piezocomposites, which had great potential to improve transducer performance. Herein, transducers (fc = 3 MHz) made of DCP and ACP 1–3 piezocomposites (prepared by PZT-5H ceramics and PMN-PT single crystals) were fabricated. The effect of the ACP method on the bandwidth and insertion loss (sensitivity) was explored. The results indicate that the ACP method can significantly enhance the bandwidth and slightly increase the insertion loss of transducers. Particularly, a superhigh bandwidth of 142.8% was achieved in the transducer of ACP 1–3 PMN-PT single crystal combined with suitable matching and backing layers. This bandwidth is higher than that of all reported transducers with similar center frequency. Moreover, the optimization mechanism of transducer performance by the ACP method was discussed. The obtained results suggested that the ACP is an effective and convenient technology to improve transducer performances, especially for the bandwidth.

Enhanced piezoelectric properties and domain morphology under alternating current electric field poled in [001]-oriented PIN-PMN-PT single crystal

The piezoelectric and dielectric properties of PMN-PT single crystals were significantly enhanced by alternating current electric field poling (ACP). In this work, to investigate the mechanisms of piezoelectric performance enhancement in relaxor ferroelectric single crystals by ACP, a [001]-oriented PIN-PMN-PT single crystal with a diameter of 3 in was grown by the modified Bridgman method, and a series of single crystal samples within 100 mm of the height of the crystal boule were prepared. Compared with their direct current electric field poling (DCP) counterparts, the electrical properties of single crystal samples at different heights by ACP were regularly enhanced. The piezoelectric coefficient d33 and the dielectric constant ɛ33 of the rhombohedral samples both increased by nearly 20%. Based on the results of polarized light microscopy, the domain wall in [001]-poled ACP samples could not be observed along the [001] direction. The brightness of polarized light propagating along the [010] orientation was enhanced after ACP. The domain images of {100} in the DCP and ACP samples were observed by piezoelectric force microscopy. The results showed that the domain size of ACP samples increased. The existence of layered domains can be clearly found in the scanning electron microscopy results of the stress fracture surface of the ACP sample. According to the analysis, the improvement of the piezoelectric performance in ACP samples comes from the elimination of the 71° domain walls. This work demonstrates that certain ACPs can regulate the domain structure and steadily improve the piezoelectric properties of R-phase PIN-PMN-PT single crystals.

Electromechanical properties and photoluminescence of Er3+-doped PMN-33PT single crystal

Based on the successful growth of large-sized Er3+-doped PMN-PT single crystal, the phase composition, electromechanical properties and photoluminescence of [001]C-oriented Er3+-doped PMN-33PT crystal were investigated in detail. The results show that the crystal coexists in rhombohedral and monoclinic phases at room temperature. The crystal possesses excellent piezoelectric (d33 ∼ 2103 pC/N), dielectric (ε33T ∼ 7589), and electromechanical coupling properties (k33 ∼ 0.91), accompanied by a higher phase transition temperature and larger coercive field compared with that of PMN-33PT single crystal. This indicates an improved electromechanical performance induced by Er3+ doping. Additionally, the crystal achieves upconversion and downconversion luminescence, and a strong dependence of the upconversion emission on temperature is demonstrated. Furthermore, a comparable optical temperature sensing performance based on the fluorescence intensity ratio of the upconversion luminescence is verified. These results demonstrate a promising multifunctional material. The electro-optical coupling performance of the Er3+-doped PMN-33PT crystal is under evaluation.

Mechanically induced rhombohedral to tetragonal phase transition in PMN–PT single crystals by nanoindentation

AbstractUnderstanding the phase transition behavior of the rhombohedral phase (R) and tetragonal phase (T) of the relaxor ferroelectric PMN–PT single crystals under mechanical load is essential for the potential voltage‐free controlled ferroelectric‐based nanodevices. Relaxor ferroelectric single crystals PMN–PT, under a local inhomogeneous mechanical load, were studied experimentally by the nanoindentation tests and Raman spectroscopy measurements. The observations show that the rhombohedral phase can be transformed successfully to the tetragonal phase under a mechanical stress, and the tetragonal phase in the PMN–PT single crystals presents a structural stability. The phase transition induced by the mechanical stress with different strain rates further indicates that the relaxor ferroelectric single crystals possess a potential mechanical controllability. The present study reveals the phase transition pathway of the relaxor ferroelectric single crystal under inhomogeneous stress and provides the exciting possibility of the control of mechanically induced phase transition for ferroelectrics.

Dependence of coercive field of PIN–PMN–PT single crystal on temperature and frequency

The effective coercive field Eceff of [001]c oriented 0.24Pb(In1/2Nb1/2)O3–0.45Pb(Mg1/3Nb2/3)O3–0.31PbTiO3 (PIN–PMN–PT) single crystals has been investigated as a function of temperature T and frequency f. The results show that the Eceff vs f curve exhibits two different regimes separated at about 400 kHz, which may be attributed to the relaxation of non-180° domain switching. It is found that Eceff linearly decreases with T at any given frequency but increases with frequency at a given temperature. These quantitative results demonstrate that the PIN–PMN–PT single crystals have good thermal stability and can be operated at a field level much beyond the conventional coercive field, revealing a great potential for high-frequency ultrasonic transducer applications.

Self-powered energy-harvesting magnetic field sensor

Driven largely by the recent growth in the Internet of Things, there is a rapid surge in the demand for low-powered or self-powered sensors and devices. Here, we report a fully self-powered magnetic sensor system based on the magnetoelectric (ME) effect. This device consists of both a field-detection element and a power-generation element, which are designed using magnetostrictive Metglas amorphous ribbons and piezoelectric PMN-PT single crystal plates, respectively. The ME laminates for energy harvesting exhibit a giant resonance magnetic responsivity of 350 nC/Oe at 15 kHz. The magnetic-field sensing element shows a linear response with a high resolution up to 32 nT, and the magnetic-harvest element can reach a power of 48.68 mW/Oe at an optimum load resistance of 5 kΩ. The self-powered sensor system has shown excellent capability to convert magnetic energy into electrical energy, as demonstrated in powering a small electronic screen. The high sensitivity and power generation of our system suggest potential applications in sustainable intelligent sensor networks.

Epitaxial integration of a perpendicularly magnetized ferrimagnetic metal on a ferroelectric oxide for electric-field control

Ferrimagnets, which contain the advantages of both ferromagnets (detectable moments) and antiferromagnets (ultrafast spin dynamics), have recently attracted great attention. Here we report the optimization of epitaxial growth of a tetragonal perpendicularly magnetized ferrimagnet Mn2Ga on MgO. Electrical transport, magnetic properties and the anomalous Hall effect (AHE) were systematically studied. Furthermore, we successfully integrated high-quality epitaxial ferrimagnetic Mn2Ga thin films onto ferroelectric PMN-PT single crystals with a MgO buffer layer. It was found that the AHE of such a ferrimagnet can be effectively modulated by a small electric field over a large temperature range in a nonvolatile manner. This work thus demonstrates the great potential of ferrimagnets for developing high-density and low-power spintronic devices.

Temperature- and electric field-dependence of polarization hysteresis for a [001]c poled PMN-PT single crystal

ABSTRACT The dynamic hysteresis scaling behaviors of a [001]c poled Pb(Mg1/3Nb2/3)O3-0.28PbTiO3 (PMN-0.28PT) single crystal have been explored as a function of amplitude E 0 and frequency f of the external electric field in a temperature region from 298 K to 388 K. The various scaling properties for hysteresis parameters such as area <A>, coercive field Ec , saturation polarization Ps vs temperature T, amplitude E 0 and frequency f were characterized among different temperature region. It was discovered that temperature has a critical influence on the polarization dynamic hysteresis and phase transformation characteristics of the PMN-0.28PT single crystal, and especially it was noticed that the discrepancy of the scaling relation between ln<A> and lnE 0 in low-field and high-field ranges decreases with increasing temperature. Meanwhile, the slope k in the linear equation ln<A> = klnE 0 + b increases while intercept b decreases with T in the temperature region of rhombohedral or tetragonal phase. In addition, temperature has a significant effect on the exponent α in the power law <A>∝ f α and the appearance of peak value in the relation between ln<A> and lnf can be mainly contributed to the frequency dependence of Ec .