Effect of diameter-to-thickness ratio of crystal disks on the vibrational characteristics of ultrasonic ceramic transducers

Mitra, Rupa

doi:10.1016/0003-682x(95)00038-b

Cited by 5 publications

(4 citation statements)

References 12 publications

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“…At distances on the order of 1000 lm, the variability in high frequency self-phase modulation (SPM) signals may thus reach an order of magnitude. The characteristic length scale of such variations is linked with the ultrasonic wavelength 30 …”

Section: Influence Of Position Across Piezotransducermentioning

confidence: 99%

“…To compare measurements from separate specimens, or widely spaced positions (more than tens of lm), one should either use adjacent regions of some kind of standard reference (e.g., an underlying substrate) or independent calibration (e.g., via laser Doppler Vibrometry). 30 Of course in the event of HF measurements where the cantilever is excited instead of the sample, 14 this limitation is removed, and other challenges can instead dominate relating to varied lever actuators, as well as the waveguide efficiency and uniformity.…”

Section: Influence Of Position Across Piezotransducermentioning

confidence: 99%

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Physical mechanisms of megahertz vibrations and nonlinear detection in ultrasonic force and related microscopies

Bosse¹,

Tovee

Huey³

et al. 2014

Journal of Applied Physics

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Use of high frequency (HF) vibrations at MHz frequencies in Atomic Force Microscopy (AFM) advanced nanoscale property mapping to video rates, allowed use of cantilever dynamics for mapping nanomechanical properties of stiff materials, sensing μs time scale phenomena in nanostructures, and enabled detection of subsurface features with nanoscale resolution. All of these methods critically depend on the generally poor characterized HF behaviour of AFM cantilevers in contact with a studied sample, spatial and frequency response of piezotransducers, and transfer of ultrasonic vibrations between the probe and a specimen. Focusing particularly on Ultrasonic Force Microscopy (UFM), this work is also applicable to waveguide UFM, heterodyne force microscopy, and near-field holographic microscopy, all methods that exploit nonlinear tip-surface force interactions at high frequencies. Leveraging automated multidimensional measurements, spectroscopic UFM (sUFM) is introduced to investigate a range of common experimental parameters, including piezotransducer excitation frequency, probed position, ultrasonic amplitude, cantilever geometry, spring constant, and normal force. Consistent with studies of influence of each of these factors, the data-rich sUFM signatures allow efficient optimization of ultrasonic-AFM based measurements, leading to best practices recommendations of using longer cantilevers with lower fundamental resonance, while at the same time increasing the central frequency of HF piezo-actuators, and only comparing results within areas on the order of few μm2 unless calibrated directly or compared with in-the-imaged area standards. Diverse materials such as Si, Cr, and photoresist are specifically investigated. This work thereby provides essential insight into the reliable use of MHz vibrations with AFM and provides direct evidence substantiating phenomena such as sensitivity to adhesion, diminished friction for certain ultrasonic conditions, and the particular benefit of UFM and related methods for nanoscale mapping of stiff materials.

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Section: Influence Of Position Across Piezotransducermentioning

confidence: 99%

Section: Influence Of Position Across Piezotransducermentioning

confidence: 99%

Physical mechanisms of megahertz vibrations and nonlinear detection in ultrasonic force and related microscopies

Bosse¹,

Tovee

Huey³

et al. 2014

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…This alleviates the need for independent calibration of the absolute ultrasonic amplitude (and hence UFM contrast) that is otherwise necessary, since it can vary on the scale of many hundreds of µm [30] due to the underlying transducer, resonant effects, or spatially dependent ultrasonic transmission. Since the m scale UFM images presented here are orders of magnitude smaller than the ultrasonic wavelength, and include an identical crystalline region in each case, they may thus be compared with confidence [31]. on topography) is apparent in the topography images by a depression in the thin film, as a result of the lower specific volume for the crystalline phase [32].…”

Section: Plan View Specimensmentioning

confidence: 99%

Nanomechanical morphology of amorphous, transition, and crystalline domains in phase change memory thin films

Bosse

Grishin

Huey

et al. 2014

Applied Surface Science

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In the search for phase change materials (PCM) that may rival traditional random access memory, a complete understanding of the amorphous to crystalline phase transition is required. For the wellknown Ge 2 Sb 2 Te 5 (GST) and GeTe (GT) chalcogenides, which display nucleation and growth dominated crystallization kinetics, respectively, this work explores the nanomechanical morphology of amorphous and crystalline phases in 50 nm thin films. Subjecting these PCM specimens to a lateral thermal gradient spanning the crystallization temperature allows for a detailed morphological investigation.Surface and depth-dependent analyses of the resulting amorphous, transition and crystalline regions are achieved with shallow angle cross-sections, uniquely implemented with beam exit Ar ion polishing. To resolve the distinct phases, ultrasonic force microscopy (UFM) with simultaneous topography is implemented revealing a relative stiffness contrast between the amorphous and crystalline phases of 14% for the free film surface and 20% for the cross-sectioned surface. Nucleation is observed to occur preferentially at the PCM-substrate and free film interface for both GST and GT, while fine subsurface structures are found to be sputtering direction dependent. Combining surface and cross-section nanomechanical mapping in this manner allows 3D analysis of microstructure and defects with nanoscale lateral and depth resolution, applicable to a wide range of materials characterization studies where the detection of subtle variations in elastic modulus or stiffness are required.

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“…Therefore, the online testing has difficulty. In addition, the probe will be abraded so seriously by the concave and convex of the pipe wall that the testing accuracy is decreased when we process the ultrasonic fast testing of residual corroded wall thickness of the gas pipe [11][12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

The Research on the Ultrasonic Focusing and TR Thickness Test Technology

Yin

Chen

et al. 2014

AMM

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A TR and ultrasonic focusing wheel probe is designed for some special engineering testing item. Ultrasonic TR thickness testing and focusing detection can be carried out without coupling medium. With the testing system and the probe set on a control machine car, aligned and marginal testing for steel plates quality and the thickness testing of corroded pipe wall can be accomplished by dry couple method. The processing method of detection signal and the design of peripheral circuit are also introduced in this paper.

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Effect of diameter-to-thickness ratio of crystal disks on the vibrational characteristics of ultrasonic ceramic transducers

Cited by 5 publications

References 12 publications

Physical mechanisms of megahertz vibrations and nonlinear detection in ultrasonic force and related microscopies

Physical mechanisms of megahertz vibrations and nonlinear detection in ultrasonic force and related microscopies

Nanomechanical morphology of amorphous, transition, and crystalline domains in phase change memory thin films

The Research on the Ultrasonic Focusing and TR Thickness Test Technology

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