BRILLOUIN-SCATTERING WITH NEUTRONS IN AN AMORPHOUS SOLID

被引：25

作者：

SUCK, JB

EGELSTAFF, PA

ROBINSON, RA

SIVIA, DS

TAYLOR, AD

机构：

[1] KERNFORSCHUNGSZENTRUM KARLSRUHE GMBH, INST NUKL FESTKORPERPHYS, W-7500 KARLSRUHE 1, GERMANY

[2] UNIV GUELPH, DEPT PHYS, GUELPH N1G 2W1, ONTARIO, CANADA

[3] LOS ALAMOS NATL LAB, LOS ALAMOS NEUTRON SCATTERING CTR, LOS ALAMOS, NM 87545 USA

[4] RUTHERFORD APPLETON LAB, ISIS FACIL, DIDCOT OX11 0QX, OXON, ENGLAND

来源：

EUROPHYSICS LETTERS | 1992年 / 19卷 / 03期

关键词：

VIBRATIONAL STATES IN DISORDERED SYSTEMS;

D O I：

10.1209/0295-5075/19/3/010

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The dispersion of collective models in the amorphous solid, Mg70Zn30, has been determined down to momentum transfers below the first pseudo-Brillouin zone for the first time using epithermal neutrons at the high-resolution time-of-flight spectrometer HET at the spallation source ISIS. In the region of Q values, where the previous experiment done with thermal neutrons and the present experiment overlap, the two sets of results agree very well. Also the previous discrepancies with the dispersion determined from the calculated one-phonon spectral function for the same metallic glass reported earlier are now less severe in the comparison with a more recent and more complete theoretical investigation of the dynamics of this glass. The extension into the first pseudo-Brillouin zone by neutron Brillouin scattering now allows this dispersion branch to be assigned to predominantly longitudinal excitations. Previously, it was erroneously assumed to be a transverse branch due to the discrepancies with the earlier theoretical results.

引用

页码：207 / 213

页数：7