scholarly journals Effect of Partial Ba Substitutions on the Crystallization of Sr2TiSi2O8 (STS) Glass–Ceramics and on the Generation of a SAW Signal at High Temperatures

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4648
Author(s):  
Maurice Gonon ◽  
Florian Dupla ◽  
Hassan Alhousseini ◽  
Marc Duquennoy ◽  
Nikolay Smagin ◽  
...  
Keyword(s):  
High Temperatures ◽  
Glass Ceramic ◽  
Acoustic Waves ◽  
High Stability ◽  
Surface Acoustic Waves ◽  
Glass Ceramics ◽  
Preferential Orientation ◽  
Ceramic Substrates ◽  
Saw Devices ◽  
Ba Substitution

Because of their characteristics, including a d33 of 10–15 pC/N and high stability up to temperatures over 1000 °C, polar glass–ceramics containing fresnoite crystals can be regarded as highly effective materials for applications requiring piezoelectricity at high temperatures. In the present paper we investigate barium substitutions in an Sr-fresnoite (STS) glass–ceramic. Two aspects are studied: first, the effect of the substitution on the preferential orientation of the crystallization, and second, the ability of the glass–ceramics to generate and propagate surface acoustic waves (SAW) at high temperatures. XRD analyses show that a 10 at.% substitution of Ba allows us to keep a strong preferential orientation of the (00l) planes of the fresnoite crystals down to more than 1 mm below the surfaces. Higher substitution levels (25 and 50 at.%), induce a non-oriented volume crystallization mechanism that competes with the surface mechanism. SAW devices were fabricated from glass–ceramic substrates with 0, 10 and 25 at.% Ba substitutions. Temperature testing reveals the high stability of the frequency and delay for all of these devices. The glass–ceramic with a 10 at.% Ba substitution gives the strongest amplitude of the SAW signal. This is attributed to the high (00l) preferential orientation and the absence of disoriented volume crystallization.

Characterization of RF Sputtered ZnO Piezoelectric Films Using Transmission Electron Microscope

1975 ◽  
Vol 33 ◽  
pp. 86-87
Author(s):  
Kemining W. Yeh ◽  
Richard S. Muller ◽  
Wei-Kuo Wu ◽  
Jack Washburn
Keyword(s):  
Integrated Circuit ◽  
Acoustic Waves ◽  
New Technology ◽  
Surface Acoustic Waves ◽  
Electromechanical Properties ◽  
Leading Role ◽  
Saw Devices ◽  
Transmission Electron ◽  
High Degree

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.

scholarly journals Nanostructure-Enhanced Surface Acoustic Waves Biosensor and Its Computational Modeling

2009 ◽  
Vol 2009 ◽  
pp. 1-11 ◽  
Author(s):  
Guigen Zhang
Keyword(s):  
Acoustic Waves ◽  
High Performance ◽  
Surface Acoustic Waves ◽  
Active Surface ◽  
Underlying Mechanism ◽  
Saw Sensor ◽  
Saw Devices ◽  
Operational Capabilities ◽  
Sensing Platform ◽  
Enhanced Surface

Surface acoustic wave (SAW) devices are considered to be very promising in providing a high-performance sensing platform with wireless and remote operational capabilities. In this review, the basic principles of SAW devices and Love-mode SAW-based biosensors are discussed first to illustrate the need for surface enhancement for the active area of a SAW sensor. Then some of the recent efforts made to incorporate nanostructures into SAW sensors are summarized. After that, a computational approach to elucidate the underlying mechanism for the operations of a Love-mode SAW biosensor with nanostructured active surface is discussed. Finally, a modeling example for a Love-mode SAW sensor with skyscraper nanopillars added to in its active surface along with some selected results is presented.

scholarly journals Epitaxial Growth of Sc0.09Al0.91N and Sc0.18Al0.82N Thin Films on Sapphire Substrates by Magnetron Sputtering for Surface Acoustic Waves Applications

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4630
Author(s):  
Florian Bartoli ◽  
Jérémy Streque ◽  
Jaafar Ghanbaja ◽  
Philippe Pigeat ◽  
Pascal Boulet ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Electromechanical Coupling ◽  
Surface Acoustic Waves ◽  
Electromechanical Coupling Coefficient ◽  
X Ray Diffraction ◽  
Plasma Parameters ◽  
Sapphire Substrates ◽  
Saw Devices ◽  
Transmission Electron ◽  
Electrical Characterizations

Scandium aluminum nitride (ScxAl1-xN) films are currently intensively studied for surface acoustic waves (SAW) filters and sensors applications, because of the excellent tradeoff they present between high SAW velocity, large piezoelectric properties and wide bandgap for the intermediate compositions with an Sc content between 10 and 20%. In this paper, the growth of Sc0.09Al0.91N and Sc0.18Al0.82N films on sapphire substrates by sputtering method is investigated. The plasma parameters were optimized, according to the film composition, in order to obtain highly-oriented films. X-ray diffraction rocking-curve measurements show a full width at half maximum below 1.5°. Moreover, high-resolution transmission electron microscopy investigations reveal the epitaxial nature of the growth. Electrical characterizations of the Sc0.09Al0.91N/sapphire-based SAW devices show three identified modes. Numerical investigations demonstrate that the intermediate compositions between 10 and 20% of scandium allow for the achievement of SAW devices with an electromechanical coupling coefficient up to 2%, provided the film is combined with electrodes constituted by a metal with a high density.

Harmonic Excitation of Surface Acoustic Waves on Gallium Nitride Thin Films for Biological and Chemical Sensor Applications

2012 ◽  
Vol 1415 ◽  
Author(s):  
J. Justice ◽  
L. E. Rodak ◽  
K. Lee ◽  
L. A. Hornak ◽  
D. Korakakis
Keyword(s):  
Thin Films ◽  
Gallium Nitride ◽  
Acoustic Waves ◽  
Chemical Sensor ◽  
Surface Acoustic Waves ◽  
Cost Effective ◽  
Harmonic Excitation ◽  
Higher Harmonics ◽  
Sensor Applications ◽  
Saw Devices

ABSTRACTGallium nitride (GaN) is a robust piezoelectric semiconductor with excellent thermal and chemical stability, making it an attractive material for surface acoustic wave (SAW) sensors operating in high temperature and harsh environments. The sensitivity of SAW devices is proportional to the square of the operating frequency. Therefore, high operating frequencies into the GHz regime are desirable for SAW sensors. For GaN, this requires sub-micron interdigital transducers (IDTs) when devices are designed to operate at the fundamental Rayleigh mode frequency. The necessity for sub-micron IDTs can increase fabrication costs and complexity. By designing SAW devices to operate at harmonic frequencies, GHz operation can be realized with relatively large IDTs, resulting in simpler and more cost effective solutions for GaN based SAW sensors. Devices have previously been designed to operate at the 5th and higher harmonics on lithium niobate, but there are no reports of using this technique on GaN in the literature. In this study, GaN thin films have been grown via metal organic vapor phase epitaxy on sapphire substrates. SAW devices designed to operate at the fundamental frequency and higher harmonics have been fabricated and measured. Operating frequencies greater than 2 GHz have been achieved using IDTs with 5 μm fingers. In addition, reduction of electromagnetic feedthrough around the 5th and 7th harmonic is demonstrated through varying ground electrode geometries.

Processing and Characterization of Efficient Thin-Film Polycrystalline-Silicon Solar Cells

2008 ◽  
Vol 1101 ◽  
Author(s):  
Ivan Gordon ◽  
Dries Van Gestel ◽  
Yu Qiu ◽  
Srisaran Venkatachalam ◽  
Guy Beaucarne ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Current Density ◽  
Glass Ceramic ◽  
Polycrystalline Silicon ◽  
Light Trapping ◽  
Glass Ceramics ◽  
Cost Effective ◽  
Ceramic Substrates ◽  
Si Solar Cells

AbstractEfficient thin-film polycrystalline-silicon (pc-Si) solar cells on inexpensive substrates could substantially lower the price of photovoltaic electricity. We recently showed that good solar cells can be made from pc-Si obtained by epitaxial thickening using thermal CVD of a seed layer made by aluminium-induced crystallization (AIC) of amorphous silicon. We already reported cells in substrate configuration with energy conversion efficiencies up to 8.0% for layers on ceramic alumina substrates. However, much higher efficiencies (η > 10%) are needed for this type of pc-Si solar cells to become cost-effective. To achieve these higher efficiencies, cells will probably have to be made in a superstrate configuration on transparent substrates and advanced light trapping will need to be applied. In this paper we report on our recent progress with pc-Si solar cells made on transparent glass-ceramic substrates.So far, our best pc-Si solar cells in substrate configuration on glass-ceramics showed an efficiency of 6.4%. By using plasma texturing to lower the front side reflection, we increased the current density of our cells by roughly 1 mA cm-2. The Jsc is much lower for cells on glass-ceramic than for cells on alumina. This is the result of the better diffuse back reflectance of alumina compared to glass. The Voc and fill factor are comparable for cells on both substrates.To make pc-Si solar cells on glass in superstrate configuration, we will use a-Si/c-Si rear junction emitters. As a first test of the feasibility of this approach, we measured the illuminated IV parameters of pc-Si cells made for the substrate configuration in superstrate configuration. In superstrate configuration, the current density of the cells is much lower than in substrate configuration due to the non-optimized cell design for superstrate illumination. The Voc is slightly smaller in superstrate configuration due to the lower current density.These results indicate that the glass-ceramic substrates are fully compatible to our poly-Si solar cell process. Furthermore, rear-junction poly-Si cells in superstrate configuration should lead to good cell results once the absorber layer thickness is optimized to the diffusion length of the material and light trapping features adapted to the superstrate configuration are applied.

Analysis of Surface Acoustic Waves in Layered Piezoelectric Media and its Applications to the Design of Saw Devices

2003 ◽  
Vol 19 (1) ◽  
pp. 225-232 ◽  
Author(s):  
T.-T. Wu ◽  
Y.-Y. Chen
Keyword(s):  
Acoustic Waves ◽  
Velocity Dispersion ◽  
Metal Layer ◽  
Effective Permittivity ◽  
Surface Acoustic Waves ◽  
Frequency Bandwidth ◽  
Piezoelectric Media ◽  
Saw Devices ◽  
Phase Velocity Dispersion

ABSTRACTIn this paper, we utilized a Stroh based formulation for solving problems of surface waves in layered piezoelectric media, and then, applied it to analyze surface acoustic wave (SAW) devices. The determination of the optimal cut of a piezoelectric crystal and the choice of the best propagation of SAW devices were given. The dispersion induced by a thin metal layer on SAW propagation in a SAW device was analyzed and discussed. Finally, we applied the formulation to calculate the effective permittivity and phase velocity dispersion of a LiNbO3/Diamond layered SAW device. Both of the null frequency bandwidth and the insertion loss of the dispersive SAW device were obtained.

Integrated ZnO Film Based Acoustic Wave Microfluidics and Biosensors

2010 ◽  
Vol 67 ◽  
pp. 49-58 ◽  
Author(s):  
Jack K. Luo ◽  
Y.Q. Fu ◽  
Greg Ashley ◽  
Williams I. Milne
Keyword(s):  
Acoustic Wave ◽  
Acoustic Waves ◽  
Low Cost ◽  
Surface Acoustic Waves ◽  
Acoustic Streaming ◽  
Film Surface ◽  
High Sensitivity ◽  
Zno Film ◽  
Actuation Mechanism ◽  
Saw Devices

Lab-on-a-chip (LOC) is one of the most important microsystems with promising applications in microanalysis, drug development and diagnosis, etc. We have been developing a LOC biodetection system using acoustic wave as a single actuation mechanism for both microfluidics and biosensing using low cost piezoelectric ZnO film. Surface acoustic waves (SAW) coupled into the liquid will induce acoustic streaming, or move the droplet on the surface. These have been utilized to make SAW-based micropumps and micromixers which are simple in structure, easy to fabricate, low cost, reliable and efficient. SAW devices and thin film bulk acoustic resonators (FBAR) have been fabricated on nanocrystalline ZnO thin films deposited using sputtering on Si substrates. A streaming velocity up to ~5cm/s within a microdroplet and a droplet moving speed of ~1cm/s have been achieved. SAW based droplet ejection and vaporization have also been realized. SAW devices and FBARs have been used to detect antibody/antigen and rabbit/goat immunoglobulin type G molecules, showing their high sensitivity. The results have demonstrated the feasibility of using a single actuation mechanism for the LOC.

scholarly journals Giant nonreciprocity of surface acoustic waves enabled by the magnetoelastic interaction

2020 ◽  
Vol 6 (49) ◽  
pp. eabc5648
Author(s):  
Piyush J. Shah ◽  
Derek A. Bas ◽  
Ivan Lisenkov ◽  
Alexei Matyushov ◽  
Nian X. Sun ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
State Of The Art ◽  
Surface Acoustic Waves ◽  
Power Reduction ◽  
Wave System ◽  
Physical Systems ◽  
Current State ◽  
Saw Devices ◽  
Communications Technologies ◽  
Microwave Communications

Nonreciprocity, the defining characteristic of isolators, circulators, and a wealth of other applications in radio/microwave communications technologies, is generally difficult to achieve as most physical systems incorporate symmetries that prevent the effect. In particular, acoustic waves are an important medium for information transport, but they are inherently symmetric in time. In this work, we report giant nonreciprocity in the transmission of surface acoustic waves (SAWs) on lithium niobate substrate coated with ferromagnet/insulator/ferromagnet (FeGaB/Al2O3/FeGaB) multilayer structure. We exploit this structure with a unique asymmetric band diagram and expand on magnetoelastic coupling theory to show how the magnetic bands couple with acoustic waves only in a single direction. We measure 48.4-dB (power ratio of 1:69,200) isolation that outperforms current state-of-the-art microwave isolator devices in a previously unidentified acoustic wave system that facilitates unprecedented size, weight, and power reduction. In addition, these results offer a promising platform to study nonreciprocal SAW devices.

scholarly journals Structure and Properties of Piezoelectric Strontium Fresnoite Glass-Ceramics Belonging to the Sr–Ti–Si–Al–K–O System

Ceramics ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 86-97 ◽  
Author(s):  
Marie-Sophie Renoirt ◽  
Nathalie Maury ◽  
Florian Dupla ◽  
Maurice Gonon
Keyword(s):  
Glass Ceramic ◽  
Mirror Symmetry ◽  
Glass Ceramics ◽  
Preferential Orientation ◽  
Surface Crystallization ◽  
High Temperature Xrd ◽  
Crystallization Conditions ◽  
The Stability ◽  
Oriented Parallel

Crystallization of strontium fresnoite Sr2TiSi2O8 piezoelectric crystals in Sr–Ti–Si–K–Al–O parent glasses is investigated with the aim of showing the influence of composition and crystallization conditions on the microstructure and piezoelectric properties of the resulting glass-ceramic. All the investigated conditions lead to a surface crystallization mechanism that induces a preferential orientation of crystal growth in the glasses. Near the surface, all the glass-ceramics obtained exhibit (002) planes preferentially oriented parallel to their faces. Deeper in the specimens, this preferential orientation is either kept or tilted to (201) after a depth of about 300 µm. The measurement of the charge coefficient d33 of the glass-ceramic highlights that surface crystallization induces mirror symmetry in the polarization. It reaches 11 to 12 pC/N and is not significantly influenced by the preferential orientation (002) or (201). High temperature XRD shows the stability of the fresnoite phase in the glass-ceramics up to 1000 °C. Mechanical characterization of the glass-ceramics by impulse excitation technique (IET) highlights that the softening of the residual glass leads to a progressive decrease of Young’s modulus in the temperature range 600–800 °C. Damping associated to the viscoplastic transition become severe only over 800 °C.

Overview on Developed Functional Plasma Sprayed Coatings on Glass and Glass Ceramic Substrates

2012 ◽  
Vol 533 ◽  
pp. 115-131
Author(s):  
Miriam Floristán ◽  
Andreas Killinger ◽  
Rainer Gadow
Keyword(s):  
Glass Ceramic ◽  
Glass Ceramics ◽  
Atmospheric Plasma ◽  
Functional Coatings ◽  
Ceramic Substrates ◽  
Substrate Activation ◽  
Plasma Sprayed Coatings ◽  
Plasma Sprayed ◽  
Sprayed Coatings ◽  
Thermo Physical Properties

For diverse applications in optical, electronic and consumer industries, the use of glass and glass ceramics as substrates for functional coatings is becoming of outstanding interest in order to develop advanced composites. Atmospheric Plasma Spraying (APS) is an adequate technology for the deposition of a wide variety of materials on glasses. Glass and glass ceramics are characterised by their specific thermo physical properties like low or even negative CTE, low heat conductivity and high dimensional stability. Consequently, modified production processes in comparison to the established coating operations on metal surfaces are required regarding the substrate activation methods or a more accurate heat transfer guidance to the substrate by optimized robot trajectories. This paper aims to give an overview of the investigations carried out at the IMTCCC for the development of plasma sprayed layer composites on borosilicate glass and glass ceramic substrates.

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