Zobrazeno 1 - 10
of 53
pro vyhledávání: '"Humphrey J"'
Publikováno v:
physica status solidi (b). 242:1379-1382
We report measurements of the sound velocity as a function of temperature in water using the picosecond acoustic interferometry technique. We show that this method can be used to make velocity measurements on very small sample volumes. (© 2005 WILEY
Autor:
Wisit Singhsomroje, Humphrey J. Maris
Publikováno v:
physica status solidi (b). 241:3463-3468
We describe experiments to study the propagation of phonon solitons in crystalline solids. A picosecond light pulse is used to generate a short strain pulse. As this pulse propagates, its shape changes as a result of phonon dispersion and elastic non
Publikováno v:
Physica B: Condensed Matter. :434-437
We describe experiments in which a sub-picosecond pump light pulse is used to excite vibrations in a nanostructure. The sample consists of a periodic array of copper wires embedded in a glass matrix on a silicon substrate. The motion of the wires aft
Publikováno v:
Ultrasonics. 56
In this paper we describe results obtained using a variation of the picosecond ultrasonics technique. We place a transparent optical mask very close to the surface of the sample. The lower surface of the mask has a series of grooves to produce a vari
Autor:
Robert J. Stoner, Cyril Cabral, Christian Lavoie, Christopher J. Morath, Guray Tas, James Mckell Edwin Harper, Humphrey J. Maris
Publikováno v:
Thin Solid Films. 374:42-48
The evolution of the phases in the cobalt–silicon reaction is studied using ultrafast optical pump-and-probe measurements. Measurements have been made on 8.5-nm thick cobalt films sputter deposited onto Si(100) substrates, and then annealed at a se
Publikováno v:
Physical Review B. 59:8105-8113
We present measurements of the lattice thermal conductivity ${\ensuremath{\kappa}}_{\ensuremath{\perp}}$ normal to the interfaces of $(\mathrm{GaAs}{)}_{n}/(\mathrm{AlAs}{)}_{n}$ superlattices with n between 1 and 40 monolayers. The conductivity was
Autor:
Humphrey J. Maris, Hsin-Yi Hao
Publikováno v:
Physica B: Condensed Matter. :670-673
Although the dispersion relation for phonons propagating in crystalline lattice has been studied for many years, the effect of lattice dispersion on the shape of a propagating pulse has not been studied experimentally. We report on an observation of
Autor:
Humphrey J. Maris, Guray Tas
Publikováno v:
Physical Review B. 55:1852-1857
We have studied the reflection of longitudinal-acoustic phonons with frequencies between 100 and 300 GHz from solid-liquid interfaces using a picosecond ultrasonic technique. Acoustic phonons were generated by absorption of a picosecond light pulse i
Autor:
W. S. Capinski, Humphrey J. Maris
Publikováno v:
Review of Scientific Instruments. 67:2720-2726
We present an improved method for making pump‐and‐probe optical measurements in the picosecond to nanosecond time range. In this type of measurement, a pump light pulse is used to excite the sample and the resulting changes in the optical propert
Autor:
Humphrey J. Maris, C.J. Morath
Publikováno v:
Physical Review B. 54:203-213
We have used a picosecond optical technique to measure the attenuation {alpha} of longitudinal-acoustic phonons in several disordered solids. We find a universal {alpha}{approximately}{nu}{sup 2} behavior for frequencies {nu} up to 320 GHz and for te