Coherent phonon dynamics in micro- and nanocrystalline diamond

Area of Science:

• Materials Science
• Condensed Matter Physics
• Spectroscopy

Background:

• Phonon dephasing is crucial for understanding thermal and electronic properties of materials.
• Micro- and nanocrystalline diamond films offer unique properties but require detailed characterization of their dynamic behavior.

Purpose of the Study:

• To investigate phonon dephasing dynamics in micro- and nanocrystalline diamond films.
• To determine the influence of film morphology and temperature on phonon dephasing times.

Main Methods:

• Time-resolved coherent anti-Stokes Raman spectroscopy (TR-CARS).
• Analysis of phonon dephasing times (T(2)) for diamond phonon modes and non-diamond carbon phases.

Main Results:

• Dephasing times (T(2)) ranged from 0.7 to 1.72 ps and were dependent on crystal size and non-diamond carbon content.
• Phonon dephasing remained temperature-independent between 10-295 K.
• A non-diamond carbon phase exhibited a very fast dephasing time of approximately 50 fs.

Conclusions:

• Film morphology significantly impacts phonon dephasing in nanocrystalline diamond.
• Phonon dephasing in these diamond films is largely insensitive to temperature variations.
• TR-CARS is effective in characterizing phonon dynamics in complex carbon materials.