scholarly journals Electromechanical Coupling Multiaxial Experimental and Micro-Constitutive Model Study of Pb(Mg1/3Nb2/3)O3- 0.32PbTiO3 Ferroelectric Single Crystal

10.5772/52540 ◽  
2012 ◽  
Author(s):  
Wan Qiang ◽  
Chen Changqing ◽  
Shen Yapeng
Keyword(s):  
Constitutive Model ◽  
Single Crystal ◽  
Electromechanical Coupling ◽  
Model Study ◽  
Ferroelectric Single Crystal

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.

Relaxor Single Crystals with Giant k31 Mode

2006 ◽  
Vol 45 ◽  
pp. 2412-2421
Author(s):  
Toshio Ogawa
Keyword(s):  
Single Crystal ◽  
Electromechanical Coupling ◽  
Impedance Measurement ◽  
Hysteresis Loops ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Poling Direction ◽  
Length Direction ◽  
Relaxor Single Crystals ◽  
The Relationship

Giant electromechanical coupling factor of k31 mode over 86% was found for (100) Pb[(Zn1/3Nb2/3)0.91Ti0.09]O3 and (110) Pb[(Mg1/3Nb2/3)0.74Ti0.26]O3 single-crystal plates poled in the [100] and [110] directions, respectively. The P-E hysteresis loops in the single-crystal plates with giant k31 became asymmetric. Furthermore, the frequency response of impedance in these plates with giant k31 consisted of a single vibration in the length direction. A mechanism to realize giant k31 can be explained by the relationship between the crystal plane and poling direction. In addition, the existence of giant piezoelectric d31 constant was proven by the strain measurement as well as by the impedance measurement.

LEAKY SURFACE ACOUSTIC WAVES IN SINGLE-CRYSTAL AlN SUBSTRATE

2004 ◽  
Vol 14 (03) ◽  
pp. 837-846 ◽  
Author(s):  
GANG BU ◽  
DAUMANTAS CIPLYS ◽  
MICHAEL S. SHUR ◽  
LEO J. SCHOWALTER ◽  
SANDRA B. SCHUJMAN ◽  
...  
Keyword(s):  
Single Crystal ◽  
Acoustic Waves ◽  
Electromechanical Coupling ◽  
Surface Acoustic Waves ◽  
Propagation Direction ◽  
Electromechanical Coupling Coefficient ◽  
Coupling Coefficients ◽  
Leaky Waves ◽  
Temperature Coefficient Of Frequency ◽  
Piezoelectric Constants

We report on the velocity V and the electromechanical coupling coefficient K2 of the first and the second leaky surface acoustic waves in various propagation directions in the a-plane AlN single-crystal. For c-propagation direction, the second leaky wave exhibited the velocity of 11016 m/s and K2 of 0.45%. For this direction, the temperature coefficient of frequency was found to be -30 ppm/°C. A near match of the velocities of the plane and leaky waves in the a-plane AlN allowed us to establish analytical relationships between the piezoelectric and elastic constants. A full set of elastic and piezoelectric constants of AlN has been evaluated by fitting the measured and calculated dependencies of velocities and electromechanical coupling coefficients on the propagation direction for both Rayleigh and leaky waves.

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