2 Synchrotron-Radiation-Based Energy-Domain Mössbauer …
77
Fig. 2.12 a Phonon density
of states (PDOS) of 57 Fe in
Al-0.017 at.% Fe [51].
b Response function of the
impurity Fe atom to the
PDOS of Al metal calculated
on the basis of Mannheim’s
impurity theory [53].
c PDOS of Al [52]
be seen by comparing Fig. 2.12a and c. The reliability of the observed spectrum
was confirmed using a Green function method that can reproduce the local PDOS
from that of the host metal and the coupling between the impurity and host atoms
[53]. The phonon spectrum calculated using this method is shown in Fig. 2.12b. It is
shown that the calculation well reproduces the measured PDOS of Fe (Fig. 2.12a).
The characteristic vibrational modes of Fe in Al were found to be modes that vibrate
resonantly with the host Al phonons. Although the measurement of the PDOS of
diluted atoms is quite difficult, this method gives clear and reliable results.
77
Fig. 2.12 a Phonon density
of states (PDOS) of 57 Fe in
Al-0.017 at.% Fe [51].
b Response function of the
impurity Fe atom to the
PDOS of Al metal calculated
on the basis of Mannheim’s
impurity theory [53].
c PDOS of Al [52]
be seen by comparing Fig. 2.12a and c. The reliability of the observed spectrum
was confirmed using a Green function method that can reproduce the local PDOS
from that of the host metal and the coupling between the impurity and host atoms
[53]. The phonon spectrum calculated using this method is shown in Fig. 2.12b. It is
shown that the calculation well reproduces the measured PDOS of Fe (Fig. 2.12a).
The characteristic vibrational modes of Fe in Al were found to be modes that vibrate
resonantly with the host Al phonons. Although the measurement of the PDOS of
diluted atoms is quite difficult, this method gives clear and reliable results.