Frequency separation of surface acoustic waves in layered structures with acoustic metamaterials

Author(s):  
D. Kalyabin ◽  
I. Lisenkov ◽  
Y.P. Lee ◽  
S. Nikitov
Author(s):  
Masashi Suzuki ◽  
Shoji Kakio

Abstract Piezoelectricity of YbAlN films has recently been shown to be almost as high as that of ScAlN films. YbAlN film surface acoustic wave (SAW) resonators are expected to have a high coupling factor. We theoretically investigated the propagation characteristics of first-mode Rayleigh SAWs (RSAWs) on Yb0.33Al0.67N film/high-velocity Si, sapphire, AlN, SiC, BN, and diamond substrates. The first-mode RSAWs on the YbAlN layered structures had high coupling factors, higher than those on ScAlN layered structures. An enhancement of the effective coupling factor of the first mode RSAWs was observed in polarity inverted YbAlN film/BN or diamond substrate structures.


Author(s):  
A.F. Belyanin ◽  
A.S. Bagdasarian ◽  
S.А. Nalimov

For the manufacture of electronic devices, layered structures based on substances characterized by a complex of unique properties are promising. These substances include AlN, which has the property of field emission, is a piezoelectric and wide-gap semiconductor material and has high hardness, thermal conductivity, sound speed, stability at high temperatures. To create microwave acoustoelectronic devices, AlN is promising as a piezoelectric material with a strong piezoelectric effect. The main factor determining the achievement and reproducibility of the necessary physicochemical properties of AlN films, in particular, piezoelectric ones, is the ordered structure of the film. To solve the problem of producing films with an ordered atomic structure, sputtering methods are promising, in particular, magnetron sputtering, the application of which has no restrictions on the synthesis temperature and requirements for the substrate material. The disadvantage of growing films by magnetron sputtering is the production of multiphase material, which requires careful refinement of the synthesis conditions and control of the properties of the resulting substances. The method of reactive RF magnetron sputtering on substrates of amorphous and crystalline materials grown AlN films with a thickness of 10 nm to 10 μm. It was established that AlN films consist of X-ray-amorphous and axially textured <0001> crystalline phases. Using electron microscopy, X-ray diffractometry, energy dispersive spectroscopy, and Raman spectroscopy, we studied the influence of synthesis conditions on the composition and structure of AlN films. The Raman spectra of light of AlN films with different contents and structure of the crystalline phase are shown. The piezoelectric efficiency of the films was determined on the models of delay lines on surface acoustic waves. Understanding the features of crystallization and phase transformations during film growth by spraying methods helps to create layered structures with controlled values of functional properties and operational characteristics. The ability to control the piezoelectric efficiency of AlN films by Raman spectra is shown.


Acoustics ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 25-41
Author(s):  
Muhammad ◽  
C.W. Lim ◽  
Andrew Y. T. Leung

The current century witnessed an overwhelming research interest in phononic crystals (PnCs) and acoustic metamaterials (AMs) research owing to their fantastic properties in manipulating acoustic and elastic waves that are inconceivable from naturally occurring materials. Extensive research literature about the dynamical and mechanical properties of acoustic metamaterials currently exists, and this maturing research field is now finding possible industrial and infrastructural applications. The present study proposes a novel 3D composite multilayered phononic pillars capable of inducing two-dimensional and three-dimensional complete bandgaps (BGs). A phononic structure that consisted of silicon and tungsten layers was subjected to both plane and surface acoustic waves in three-dimensional and two-dimensional periodic systems, respectively. By frequency response study, the wave attenuation, trapping/localization, transmission, and defect analysis was carried out for both plane and surface acoustic waves. In the bandgap, the localized defect state was studied for both plane and surface acoustic waves separately. At the defect state, the localization of both plane and surface acoustic waves was observed. By varying the defect size, the localized frequency can be made tailorable. The study is based on a numerical technique, and it is validated by comparison with a reported theoretical work. The findings may provide a new perspective and insight for the designs and applications of three-dimensional phononic crystals for surface acoustic wave and plane wave manipulation, particularly for energy harvesting, sensing, focusing and waves isolation/attenuation purposes.


Author(s):  
Kemining W. Yeh ◽  
Richard S. Muller ◽  
Wei-Kuo Wu ◽  
Jack Washburn

Considerable and continuing interest has been shown in the thin film transducer fabrication for surface acoustic waves (SAW) in the past few years. Due to the high degree of miniaturization, compatibility with silicon integrated circuit technology, simplicity and ease of design, this new technology has played an important role in the design of new devices for communications and signal processing. Among the commonly used piezoelectric thin films, ZnO generally yields superior electromechanical properties and is expected to play a leading role in the development of SAW devices.


1998 ◽  
Vol 77 (5) ◽  
pp. 1195-1202
Author(s):  
Andreas Knabchen Yehoshua, B. Levinson, Ora

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