19–24 May 2024
Music City Center
US/Central timezone

Thermal diffusivity and acoustic properties of Nb thin films studied by time-domain thermoreflectance

THPR63
23 May 2024, 16:00
2h
Rock 'n Roll (MCC Exhibit Hall A)

Rock 'n Roll

MCC Exhibit Hall A

Poster Presentation MC8.U02 Materials Analysis and Modification Thursday Poster Session

Speaker

Md Obidul Islam (Old Dominion University)

Description

The thermal diffusion and acoustic properties of Nb impacts the thermal management of devices incorporating Nb thin films such as superconducting radiofrequency (SRF) cavities and superconducting high-speed electronic devices. The diffusion and acoustic properties of 200-800 nm thick Nb films deposited on Cu substrates were investigated using time-domain thermoreflectance (TDTR). The films were examined by X-ray diffraction, scanning electron microscopy, and atomic force microscopy. The grain size and thermal diffusivity increase with film thickness. The thermal diffusivity increased from 0.100± 0.002 cm2s-1 to 0.237± 0.002 cm2s-1 with the increase in film thickness from 200 nm (grain size 20±6 nm) to 800 nm (grain size 65±16 nm). Damped periodic photoacoustic signals are detected due to laser heating generated stress in the Nb film, which results in an acoustic pulse bouncing from the Nb/Cu and the Nb/vacuum interfaces. The period of the acoustic oscillation gives a longitudinal sound velocity of 3637.3 ms-1 inside the Nb films, which is in good agreement with the values reported in the literature.

Region represented North America
Paper preparation format Word

Primary author

Md Obidul Islam (Old Dominion University)

Co-author

Hani Elsayed-Ali (Old Dominion University)

Presentation materials

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