The Effective Electromechanical Moduli of Domain Engineered Ferroelectric Crystals

Aerospace ◽  
2003 ◽  
Author(s):  
Jiangyu Li ◽  
Dan Liu
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Electromechanical Coupling ◽  
Fundamental Property ◽  
Homogenization Theory ◽  
Optimal Domain ◽  
Design And Optimization ◽  
Domain Configuration ◽  
Ferroelectric Single Crystal ◽  
Minimization Approach

We present a micromechanical analysis to explain the enhanced electromechanical coupling of domain engineered ferroelectric single crystals. The theory starts with energy-minimization approach, where the energy minimizing domain configurations are characterized as the convex hull of the ferroelectric energy wells, and are constructed by multi-rank laminations. The electromechanical moduli of ferroelectric single crystal with engineered domain configuration can then be determined by the homogenization theory. Using this approach, we analyzed the engineered domain configuration in tetragonal single crystal BaTiO3 poled in <111> direction, where d33 70% higher than those poled in <001> direction has been demonstrated, consistent with experimental observation. It is also found that the two-variant domain configurations have higher enhancement than three-variant systems, suggesting an optimal domain configuration for the enhanced piezoelectric properties. The theory reveals the fundamental property enhancement mechanism in ferroelectric single crystals with engineered domain configuration, and offers insight on the design and optimization of ferroelectric single crystals with superior functional properties.

scholarly journals The Design and Optimization of a Compressive-Type Vector Sensor Utilizing a PMN-28PT Piezoelectric Single-Crystal

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5155
Author(s):  
Hong Goo Yeo ◽  
Junhee Choi ◽  
Changzhu Jin ◽  
Seonghun Pyo ◽  
Yongrae Roh ◽  
...  
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Axial Vector ◽  
Geometric Optimization ◽  
Voltage Sensitivity ◽  
Element Analysis ◽  
Design And Optimization ◽  
Seismic Mass ◽  
Vector Sensor ◽  
Dipole Pattern

Underwater sensors that detect the distance and direction of acoustic sources are critical for surveillance monitoring and target detection in the water. Here, we propose an axial vector sensor that utilizes a small (~1 cm3) compressive-type piezoelectric accelerometer using piezoelectric single crystals. Initially, finite element analysis (FEA) was used to optimize the structure that comprised piezoelectric Pb(Mb1/3Nb2/3)O3-28%PbTiO3 single crystals on a tungsten seismic mass. The receiving voltage sensitivity (RVS) was enhanced through geometric optimization of the thickness and sensing area of the piezoelectric material and the seismic mass. The estimated maximum RVS of the optimized vector sensor was −212 dB. FEA simulations and practical measurements were used to verify the directivity of the vector sensor design, which exhibited a dipole pattern. The dipole beam pattern was used to obtain cardioid patterns using the simulated and measured results for comparison. The results clearly showed the feasibility of using the proposed piezoelectric single-crystal accelerometer for a compressive-type vector sensor.

scholarly journals Bridgman Growth and Photoelectronic Property of Relaxor-Based Ferroelectric Single Crystal Pb(Sm1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 402
Author(s):  
Fan Liao ◽  
Yan Zhao ◽  
Ziyun Chen ◽  
Yanqing Zheng ◽  
Hongbing Chen
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Direct Current ◽  
Optical Transmittance ◽  
Alternating Current ◽  
Nominal Composition ◽  
Structure Changes ◽  
Current Voltage ◽  
Vertical Bridgman ◽  
Ferroelectric Single Crystal

A relaxor-based ferroelectric single crystal with the nominal composition of xPb(Sm0.5Nb0.5)O3-(0.7‒x) Pb(Mg1/3Nb1/3)O3-0.3PbTiO3 (x = 0.01, 0.02, and 0.03) was grown by the vertical Bridgman process. The electrical properties and the ferroelectric domains, as well as the luminescent characteristics of the single crystals, were investigated systematically. The piezoelectric coefficient d33 of the single crystals are slightly higher than that of the undoped PMN-PT single crystal under direct current polarization, while the crystal wafers gain a much higher d33 value upon being polarized with alternating current voltage. The single crystals possess a decreased phase transition temperature of around 60 °C and a decreased Curie temperature of 92~116 °C compared with the undoped PMN-PT single crystal. The crystal wafers polarized with alternating current voltage exhibited a desirable optical transmittance, which is associated with the domain structure changes inside the crystal medium. The domain density of the crystal wafers under alternating current polarization was significantly decreased compared with the direct current polarized crystal wafers. The luminescent spectra of the crystal wafers exhibit the typical emission peaks corresponding to the characteristic transition of Sm3+ ions in the crystal lattice.

High-accuracy polarimetric studies on lead germinate single crystals

2021 ◽  
Vol 54 (6) ◽  
Author(s):  
Mykola Shopa ◽  
Nazar Ftomyn ◽  
Yaroslav Shopa
Keyword(s):  
Electric Field ◽  
Single Crystal ◽  
Single Crystals ◽  
Hysteresis Loops ◽  
High Accuracy ◽  
Tensor Component ◽  
Lead Germanate ◽  
Measurement Results ◽  
Ferroelectric Single Crystal

A high-accuracy polarimetric technique has been used for the characterization of a lead germanate ferroelectric single crystal. The measurement results of the linear and circular birefringence in the [010] direction at a wavelength of 633 nm under the influence of an electric field are presented. Gyration–electric field hysteresis loops at alternative crystal positions in the polarization system have been used to determine the ellipticity of the eigenwaves. A temperature dependence of the gyration tensor component g 11 in the temperature range of 300–450 K was found.

scholarly journals “Generation III” Piezoelectric Single Crystals Developed by Solid-State Single Crystal Growth Method

Ceramist ◽  
2021 ◽  
Vol 24 (3) ◽  
pp. 273-285
Author(s):  
Ho-Yong LEE
Keyword(s):  
Crystal Growth ◽  
Solid State ◽  
Single Crystal ◽  
Single Crystals ◽  
Electromechanical Coupling ◽  
Single Crystal Growth ◽  
Ultrasonic Transducers ◽  
Coupling Coefficients ◽  
Growth Method ◽  
Piezoelectric Constants

Crystallographically engineered Relaxor-PT single crystals, specifically PMN-PT (Generation I) and PIN-PMN-PT/PMN-PZT (Generation II), offer much higher piezoelectric and electromechanical coupling coefficients (d33>1,500 pC/N, k33>0.9), when compared to polycrystalline PZT-5H ceramics (d33>600 pC/N, k33>0.75). Recently Ceracomp Co., Ltd. (www.ceracomp.com) has developed the solid-state single crystal growth (SSCG) technique and successfully fabricated Gen III PMN-PZT single crystals modified with acceptors or donors. The piezoelectric constants (d33) of (001) Gen III PMN-PZT single crystals were measured to be higher than 4,000 pC/N and thus about two times higher than those of PMN-PT/PZN-PT (Gen I) and PIN-PMN-PT/PMN-PZT (Gen II) single crystals. The Gen III PMN-PZT single crystals have been firstly applied to single crystal-epoxy composites, ultrasonic transducers, piezoelectric sensors, and piezoelectric actuators. In this paper we introduce the development of Gen III PMN-PZT single crystals, piezoelectric composites and multilayer single crystal actuators.

The observation of defects on (100) CdTe surfaces by chemical etching

1992 ◽  
Vol 50 (2) ◽  
pp. 1424-1425
Author(s):  
M.E. Lee
Keyword(s):  
Single Crystal ◽  
Grain Boundaries ◽  
Single Crystals ◽  
Chemical Etching ◽  
Crystalline Perfection ◽  
Crystalline Defects ◽  
High Incidence ◽  
Crystallographic Defects ◽  
Cdznte Substrates ◽  
Device Technology

The crystalline perfection of bulk CdTe substrates plays an important role in their use in infrared device technology. The application of chemical etchants to determine crystal polarity or the density and distribution of crystallographic defects in (100) CdTe is not well understood. The lack of data on (100) CdTe surfaces is a result of the apparent difficulty in growing (100) CdTe single crystal substrates which is caused by a high incidence of twinning. Many etchants have been reported to predict polarity on one or both (111) CdTe planes but are considered to be unsuitable as defect etchants. An etchant reported recently has been considered to be a true defect etchant for CdTe, MCT and CdZnTe substrates. This etchant has been reported to reveal crystalline defects such as dislocations, grain boundaries and inclusions in (110) and (111) CdTe. In this study the effect of this new etchant on (100) CdTe surfaces is investigated.The single crystals used in this study were (100) CdTe as-cut slices (1mm thickness) from Bridgman-grown ingots.

Mounting an individual submicrometer sized single crystal

1996 ◽  
Vol 211 (6) ◽  
Author(s):  
R. B. Neder ◽  
M. Burghammer ◽  
Th. Grasl ◽  
H. Schulz
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Single Crystal ◽  
Single Crystals ◽  
High Vacuum ◽  
Nanometer Resolution ◽  
Micro Manipulator ◽  
Scanning Electron

AbstractWe developed a new micro manipulator for mounting individual sub-micrometer sized single crystals within a scanning electron microscope. The translations are realized via a commercially available piezomicroscope, adapted for high vacuum usage and realize nanometer resolution. With this novel instrument it is routinely possible to mount individual single crystals with sizes down to 0.1

Study of potential oscillations during reaction of an aluminium single crystal with an aqueous KOH solution

1990 ◽  
Vol 55 (2) ◽  
pp. 345-353 ◽  
Author(s):  
Ivan Halaša ◽  
Milica Miadoková
Keyword(s):  
Aqueous Solutions ◽  
Single Crystal ◽  
Single Crystals ◽  
Periodic Potential ◽  
Optimum Conditions ◽  
Potential Oscillations ◽  
Dilute Aqueous Solutions ◽  
Experimental Findings ◽  
Kinetics Of

The authors investigated periodic potential changes measured on oriented sections of Al single crystals during spontaneous dissolution in dilute aqueous solutions of KOH, with the aim to find optimum conditions for the formation of potential oscillations. It was found that this phenomenon is related with the kinetics of the reaction investigated, whose rate also changed periodically. The mechanism of the oscillations is discussed in view of the experimental findings.

Measurement of growth rates for single crystals and pressed tablets of CuSO4.5 H2O on a rotating disc

1989 ◽  
Vol 54 (11) ◽  
pp. 2951-2961 ◽  
Author(s):  
Miloslav Karel ◽  
Jaroslav Nývlt
Keyword(s):  
Growth Rate ◽  
Single Crystal ◽  
Single Crystals ◽  
Growth Rates ◽  
Diffusion Coefficients ◽  
Preferred Orientation ◽  
Rotating Disc ◽  
Dissolution Rates ◽  
Rates Of Growth ◽  
Good Agreement

Measured growth and dissolution rates of single crystals and tablets were used to calculate the overall linear rates of growth and dissolution of CuSO4.5 H2O crystals. The growth rate for the tablet is by 20% higher than that calculated for the single crystal. It has been concluded that this difference is due to a preferred orientation of crystal faces on the tablet surface. Calculated diffusion coefficients and thicknesses of the diffusion and hydrodynamic layers in the vicinity of the growing or dissolving crystal are in good agreement with published values.

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