Accession Number:

ADA191727

Title:

Electron-Rayleigh Wave Interaction in Thin Film Carbons.

Descriptive Note:

Rept. for 1 Sep 86-31 Aug 87,

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE

Personal Author(s):

• Sugihara, K.

Report Date:

1987-10-30

Pagination or Media Count:

4.0

Abstract:

Sound wave propagation in thin film carbon is investigated in the long wavelength approximation. Strain-free and stress-free boundary conditions lead to the same solution. The Rayleigh wave, with a small damping constant and with polarization perpendicular to the layer planes, has a small sound velocity. Since the long wavelength phonon energies associated with this wave are very small, these phonon are readily excited even at very low temperatures. Furthermore, those phonons strongly scatter carriers at low temperatures. Of particular interest for transport properties is the determination of the carrier relaxation time for very thin film thicknesses. These phonons are also responsible for the temperature dependence of the negative magnetoresistance of pregraphitic carbons at low temperatures. Keywords Interaction of electrons, Rayleigh waves graphite films, Electron scattering.

Descriptors:

• *CARBON
• *RAYLEIGH WAVES
• *THIN FILMS
• ACOUSTIC VELOCITY
• BOUNDARIES
• DAMPING
• ELECTRON SCATTERING
• ELECTRONS
• ENERGY
• FILMS
• GRAPHITE
• INTERACTIONS
• LONG WAVELENGTHS
• LOW TEMPERATURE
• MAGNETORESISTANCE
• PHONONS
• RELAXATION TIME
• SOUND TRANSMISSION
• SOUND WAVES
• STRESSES
• TEMPERATURE
• THICKNESS
• TRANSPORT PROPERTIES

Subject Categories:

• Inorganic Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE