8 Mössbauer Spectroscopy in External Magnetic Fields
421
Fig. 8.40 Room
temperature 57 Fe Mössbauer
spectra of typical Y(Fe,Al) 2
samples [141]. Reprinted by
permission from Springer:
Hyperfine Interactions,
Electrostatic hyperfine
interactions Y(fe, Al) 2 , M.
Reissner, W. Steiner,
copyright (1986)
Fig. 8.41 Temperature
dependence of the mean
quadrupole splitting Q, mean
centre shift CS (rel. 57 CoRh)
and half width /2 of
Y(Fe 0.4 Al 0.6 ) 2 . Adapted
from [143]
ting is present. The transition temperature T A , where magnetic hyperfine splitting
appears, is well defined by a strong increase of half width, if spectra are still fitted by
superposition of quadrupole split spectra (Fig. 8.41). T A is in good agreement with
the ordering temperature T c obtained from the magnetic measurements on the Fe-rich
side, whereas it is slightly higher than T M on the Al-rich side, which is as mentioned
above typical for spin glass behaviour and caused by the different time scales of the
experiments (Fig. 8.42). The range above the ordering temperature where non-linear
421
Fig. 8.40 Room
temperature 57 Fe Mössbauer
spectra of typical Y(Fe,Al) 2
samples [141]. Reprinted by
permission from Springer:
Hyperfine Interactions,
Electrostatic hyperfine
interactions Y(fe, Al) 2 , M.
Reissner, W. Steiner,
copyright (1986)
Fig. 8.41 Temperature
dependence of the mean
quadrupole splitting Q, mean
centre shift CS (rel. 57 CoRh)
and half width /2 of
Y(Fe 0.4 Al 0.6 ) 2 . Adapted
from [143]
ting is present. The transition temperature T A , where magnetic hyperfine splitting
appears, is well defined by a strong increase of half width, if spectra are still fitted by
superposition of quadrupole split spectra (Fig. 8.41). T A is in good agreement with
the ordering temperature T c obtained from the magnetic measurements on the Fe-rich
side, whereas it is slightly higher than T M on the Al-rich side, which is as mentioned
above typical for spin glass behaviour and caused by the different time scales of the
experiments (Fig. 8.42). The range above the ordering temperature where non-linear