TY - JOUR
T1 - Neutron diffraction from sound-excited crystals
AU - Remhof, A.
AU - Liß, K. D.
AU - Magerl, A.
N1 - Copyright:
Copyright 2007 Elsevier B.V., All rights reserved.
PY - 1997/6/11
Y1 - 1997/6/11
N2 - A longitudinal sound wave modulates the regular arrangement of the atomic planes of a crystal in two ways: first, the spacing between the atomic planes is modified in the regions of compression and expansion introducing a macroscopic strain and, second, the lattice planes acquire a velocity in the oscillating strain field. Bragg reflection in a strained crystal maintains the energy of the radiation, whereas Bragg reflection by a moving lattice provokes a Doppler shift of the radiation. In a diffraction experiment both these effects lead to an enlarged bandwidth of the reflection curve. The relative importance of strain and Doppler depends mainly on the radiation used. For thermal neutron scattering the profile of the rocking curve of a Bragg reflection may permit to separate the two effects. Atomic amplitudes of the sound field of 136 Å peak to peak in the bulk of the crystal can be deduced from the rocking profile. The enlarged bandwidth of a sound-excited crystal opens a possibility for diffraction-based optical elements where the trade-off between resolution and intensity can be readily modified.
AB - A longitudinal sound wave modulates the regular arrangement of the atomic planes of a crystal in two ways: first, the spacing between the atomic planes is modified in the regions of compression and expansion introducing a macroscopic strain and, second, the lattice planes acquire a velocity in the oscillating strain field. Bragg reflection in a strained crystal maintains the energy of the radiation, whereas Bragg reflection by a moving lattice provokes a Doppler shift of the radiation. In a diffraction experiment both these effects lead to an enlarged bandwidth of the reflection curve. The relative importance of strain and Doppler depends mainly on the radiation used. For thermal neutron scattering the profile of the rocking curve of a Bragg reflection may permit to separate the two effects. Atomic amplitudes of the sound field of 136 Å peak to peak in the bulk of the crystal can be deduced from the rocking profile. The enlarged bandwidth of a sound-excited crystal opens a possibility for diffraction-based optical elements where the trade-off between resolution and intensity can be readily modified.
KW - Diffraction
KW - Neutron optics
KW - Solid state dynamics
KW - Ultrasound
UR - http://www.scopus.com/inward/record.url?scp=0031163221&partnerID=8YFLogxK
U2 - 10.1016/S0168-9002(97)00411-7
DO - 10.1016/S0168-9002(97)00411-7
M3 - 文章
AN - SCOPUS:0031163221
VL - 391
SP - 485
EP - 491
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
SN - 0168-9002
IS - 3
ER -