Shear mode electromechanical coupling coefficient k15 and crystallites alignment of (112¯0) textured ZnO films

2007 ◽  
Vol 102 (2) ◽  
pp. 024110 ◽  
Author(s):  
Takahiko Yanagitani ◽  
Masato Kiuchi ◽  
Mami Matsukawa ◽  
Yoshiaki Watanabe
Keyword(s):  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Coefficient ◽  
Zno Films ◽  
Shear Mode

The Investigation of Preferred Orientation Growth of ZnO Films on the Ceramic Substrates

2003 ◽  
Vol 764 ◽  
Author(s):  
Sheng-Yuan Chu ◽  
Te-Yi Chen ◽  
Walter Water ◽  
Tung-Yi Huang
Keyword(s):  
Coupling Coefficient ◽  
Gas Flow ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Coefficient ◽  
Zno Films ◽  
Ceramic Substrates ◽  
Force Microscopy ◽  
Atomic Force ◽  
Gas Flow Ratio ◽  
Temperature Coefficient Of Frequency

AbstractPoly-crystal ZnO films with c-axis (002) orientation have been successfully grown on the lead-based ceramic substrates by r.f. magnetron sputtering technique. The deposited films were characterized as a function of deposition time and argon-oxygen gas flow ratio. Crystalline structures of the films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Highly oriented films with c-axis normal to the substrates can be obtained by depositing under a total pressure of 10mTorr containing 50% argon and 50% oxygen and r.f. power of 70W for 3 hours. The phase velocity, electromechanical coupling coefficient and temperature coefficient of frequency of SAW device with ZnO/IDT/PT-ceramic structure were investigated. It shows that the preferred oriented ZnO film is beneficial for improving the electromechanical coupling coefficient of SAW device.

Modal effective electromechanical coupling coefficient of shear-mode piezoceramic sandwich cantilevers with segmented multicore: Experimental and numerical assessments

2020 ◽  
pp. 107754632097290
Author(s):  
Pelin Berik ◽  
Ayech Benjeddou
Keyword(s):  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Performance Indicator ◽  
Numerical Models ◽  
Short Circuit ◽  
Smart Structures ◽  
Coupling Efficiency ◽  
Electromechanical Coupling Coefficient ◽  
Shear Mode ◽  
Effective Electromechanical Coupling Coefficient

Smart sandwich cantilevers with aluminum faces and single and double cores, formed by assembled shear-mode piezoceramic patches with same poling, are experimentally and numerically assessed for the first time. To measure the electromechanical coupling efficiency of such vibrating smart structures, the so-called modal effective electromechanical coupling coefficient is used as a performance indicator. Hence, it is first experimentally analyzed under different electric connections (short circuit, open circuit, series wiring, and parallel wiring) of the patches’ electrodes; then, it is numerically investigated for models with different refinements (equipotential constraints and bonding adhesives) using ABAQUS® three-dimensional finite element simulations. It is found that the experimental modal effective electromechanical coupling coefficient is low for the smart shear-mode piezoceramic single core sandwich but can be increased using multilayer designs, as confirmed by the smart shear-mode piezoceramic double core sandwich. Numerically, it is found that the electric connection has less influence on the modal effective electromechanical coupling coefficient evaluation than the equipotential constraints and adhesives modeling, in particular for the smart shear double core sandwich. The proposed two benchmarks can be used by the research community of smart structures, systems, and devices for validating new shear-mode response-based theories and numerical models or designing related engineering applications, such as shunted damping, energy harvesting, structural health monitoring, resonators, and filters.

Sb5+ Modified Phase Transition in (Li, Na, K)(Nb1-xSbx)O3 Piezoelectric Ceramics

2016 ◽  
Vol 848 ◽  
pp. 339-343
Author(s):  
Xiao Kun Zhao ◽  
Bo Ping Zhang ◽  
Lei Zhao ◽  
Li Feng Zhu
Keyword(s):  
Phase Transition ◽  
Phase Boundary ◽  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Piezoelectric Coefficient ◽  
Electromechanical Coupling Coefficient ◽  
Second Phase ◽  
Phase Transition Temperatures ◽  
Two Peaks ◽  
Planar Mode

The modified behavior of the phase transition temperatures (TO-T and/or TC) between orthorhombic (O), tetragonal (T) and cubic (C) that caused by doping Sb5+ in (Li0.052Na0.493K0.455)(Nb1-xSbx)O3 (LNKNSx) ceramics was reported in the present investigation. The results show that differing from the insensitive TO-T to the Sb5+ content, TC splits into two peaks TCI and TCII when doping Sb5+. The decreased TCI by raising x may be ascribed to the Sb-rich grains and the settled TCII round 480 °C resulting from the Sb-lack ones. The enhanced piezoelectric coefficient d33 value of 263 pC/N and planar mode electromechanical coupling coefficient kp value of 42.5% at x=0.052 can be attributed to the polymorphic phase boundary (PPB) behavior with an appropriate ratio between T and O phases without any second phase.

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