Mechanical and acoustic properties of nm devices studied by GHz-THz ultrasonics
- Overview of Technology
Ultrasonic measurement is an important technique that is used in various fields of science and technology, including physical property evaluation, imaging and sensing. I use a measurement technique that uses light to excite and detect ultrasonic waves in the frequency range of GHz to THz, and I use this to evaluate the mechanical and acoustic properties of microstructures and thin films with sizes in the nano to micro range, as well as for non-destructive testing.
- Comparison with Conventional Technology
Conventional ultrasound had a wavelength of several micrometres or more, so it was impossible to measure at the nanoscale.
However, by using femtosecond pulse lasers to manipulate ultrasound with a wavelength of the order of 10 nm, I have achieved the evaluation of the mechanical properties of nano-materials and non-destructive testing in the nano-region.- Features and Uniqueness
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- Development of unique measurement technology that makes full use of light and sound (lasers and ultrasound)
- Excitation and detection of vibration phenomena in nano-materials and GHz bands
- Accurate measurement of sound velocity and elastic constants under high magnetic fields of 10 to 600 K and up to 5 T
- Measurement of magnetic damping constants and saturation magnetisation from magnetisation oscillations in the time domain
- Main targets include nano-thin films of metals, piezoelectric materials, and magnetic materials, as well as superhard materials such as diamond and tungsten carbide
- Contributing to the development of materials and the elucidation of the characteristics of filters for wireless communication in smartphones
- Applications include the development of highly sensitive biosensors using ultrasound, which has a shorter wavelength than light, and monitoring the breaking process of nanowires
- Practical Application
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This measurement method enables the inspection of defects in semiconductors on the order of nm, and the evaluation of the characteristics of acoustic filters, which are essential for 5G communication devices.
- Keywords
Researchers
Graduate School of Engineering
Division for the Establishment of Frontier Sciences of Organization for Advanced Studies
Akira Nagakubo, Associate Professor
PhD. Engineering
By using femto-second pulse laser, I can excite and detect nm/GHz ultrasonics to evaluate mechanical and acoustic properties of nano film and nano wire. This techniques enables NDE within nano order.