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.

Characteristics Analysis of Saw Filter Using Al0.36Ga0.64N Thin Film

2002 ◽  
Vol 720 ◽  
Author(s):  
Sun-Ki Kim ◽  
Min-Jung Park ◽  
Cheol-Yeong Jang ◽  
Hyun-Chul Choi ◽  
Jung-Hee Lee ◽  
...  
Keyword(s):  
Thin Film ◽  
Insertion Loss ◽  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Side Lobe ◽  
Electromechanical Coupling Coefficient ◽  
Device Performance ◽  
Saw Devices ◽  
Characteristics Analysis ◽  
Temperature Coefficient Of Frequency

AbstractAlxGa1-xN sample with x=0.36 was epitaxially grown on sapphire by MOCVD. SAW velocity of 5420 m/s and TCF (temperature coefficient of frequency) of -51.20 ppm/°C were measured from the SAW devices fabricated on the AlxGa1-xN sample, when kh value was 0.078, at temperatures between –30 °C and 60 °C Electromechanical coupling coefficient was ranged from 1.26 % to 2.22 %. The fabricated SAW filter have shown a good device performance with insertion loss of -33.853 dB and side lobe attenuation of 20 dB.

scholarly journals Synthesis of ultrasmooth nanostructured diamond films by microwave plasma chemical vapor deposition using a He/H2/CH4/N2gas mixture

2006 ◽  
Vol 21 (10) ◽  
pp. 2675-2682 ◽  
Author(s):  
S. Chowdhury ◽  
Damon A. Hillman ◽  
Shane A. Catledge ◽  
Valery V. Konovalov ◽  
Yogesh K. Vohra
Keyword(s):  
Gas Flow ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Optical Emission ◽  
X Ray Diffraction ◽  
Plasma Chemical Vapor Deposition ◽  
Force Microscopy ◽  
Atomic Force ◽  
Gas Flow Ratio

Ultrasmooth nanostructured diamond (USND) films were synthesized on Ti–6Al–4V medical grade substrates by adding helium in H2/CH4/N2plasma and changing the N2/CH4gas flow from 0 to 0.6. We were able to deposit diamond films as smooth as 6 nm (root-mean-square), as measured by an atomic force microscopy (AFM) scan area of 2 μm2. Grain size was 4–5 nm at 71% He in (H2+ He) and N2/CH4gas flow ratio of 0.4 without deteriorating the hardness (∼50–60 GPa). The characterization of the films was performed with AFM, scanning electron microscopy, x-ray diffraction (XRD), Raman spectroscopy, and nanoindentation techniques. XRD and Raman results showed the nanocrystalline nature of the diamond films. The plasma species during deposition were monitored by optical emission spectroscopy. With increasing N2/CH4feedgas ratio (CH4was fixed) in He/H2/CH4/N2plasma, a substantial increase of CN radical (normalized by Balmer Hαline) was observed along with a drop in surface roughness up to a critical N2/CH4ratio of 0.4. The CN radical concentration in the plasma was thus correlated to the formation of ultrasmooth nanostructured diamond films.

scholarly journals Ultrahigh Electromechanical Coupling and Its Thermal Stability in (Na1/2Bi1/2)TiO3-Based Lead-Free Single Crystals

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 435
Author(s):  
Chao Chen ◽  
Li Yang ◽  
Xingan Jiang ◽  
Xiaokun Huang ◽  
Xiaoyi Gao ◽  
...  
Keyword(s):  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Lead Free ◽  
Electromechanical Coupling Coefficient ◽  
Force Microscopy ◽  
Scattering Spectra ◽  
Raman Scattering Spectra ◽  
Piezoelectric Force Microscopy ◽  
Microscopy Characterization ◽  
Thickness Mode

In this work, we report the ultrahigh electromechanical coupling performance of NBT-6BT-KNN lead-free single crystal at room temperature. The thickness mode electromechanical coupling coefficient (kt) and the 31 mode electromechanical coupling coefficient (k31) reach 69.0% and 45.7%, respectively, which are superior to the PZT-5H lead-based ceramics of kt~60% and k31~39%. In addition, the evolution of the crystal structure and domain morphology is revealed by Raman scattering spectra, a polarizing microscope and piezoelectric force microscopy characterization.

scholarly journals Love Wave Ultraviolet Photodetector Fabricated on a TiO2/ST-Cut Quartz Structure

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Walter Water ◽  
Yi-Shun Lin ◽  
Chi-Wei Wen
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Temperature Coefficient ◽  
Coupling Coefficient ◽  
Love Wave ◽  
Electromechanical Coupling ◽  
Quartz Substrate ◽  
Electromechanical Coupling Coefficient ◽  
Ultraviolet Photodetector ◽  
Temperature Coefficient Of Frequency

A TiO2thin film deposited on a 90° rotated 42°45′ ST-cut quartz substrate was applied to fabricate a Love wave ultraviolet photodetector. TiO2thin films were grown by radio frequency magnetron sputtering. The crystalline structure and surface morphology of TiO2thin films were examined using X-ray diffraction, scanning electron microscope, and atomic force microscope. The effect of TiO2thin film thickness on the phase velocity, electromechanical coupling coefficient, temperature coefficient of frequency, and sensitivity of ultraviolet of devices was investigated. TiO2thin film increases the electromechanical coupling coefficient but decreases the temperature coefficient of frequency for Love wave propagation on the 90° rotated 42°45′ ST-cut quartz. For Love wave ultraviolet photodetector application, the maximum insertion loss shift and phase shift are 2.81 dB and 3.55 degree at the 1.35-μm-thick TiO2film.

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
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