8 Mössbauer Spectroscopy in External Magnetic Fields
439
Fig. 8.62 Energy level
scheme of the two states
which are allowed in the
model with and without B a
[158]. © IOP Publishing.
Reproduced with permission.
All rights reserved
Fig. 8.63 Dependence of
τ on /τ of f on T for different
B a in Y(Fe 0.75 Al 0.25 ) 2 [158].
© IOP Publishing.
Reproduced with permission.
All rights reserved
magnetism is in fact a ferrimagnet. For RE 6 Fe 13 X compounds the comparison of
magnetic investigations with high field Mössbauer results it is shown that even in the
highest applied fields the spin moments are canted. In Fe pnictides crystallographically only one Fe site is present, which should lead to only one simple Mössbauer
spectrum, which is indeed found in zero field measurements. With the application
of an external field, spectra become so complex, that they cannot be explained by
only one subspectrum. This is only one example that the external field opens a new
window for elucidation of real magnetic ground states, which are not visible without
field. In the last example the magnetic behaviour of spin glasses is discussed. After
439
Fig. 8.62 Energy level
scheme of the two states
which are allowed in the
model with and without B a
[158]. © IOP Publishing.
Reproduced with permission.
All rights reserved
Fig. 8.63 Dependence of
τ on /τ of f on T for different
B a in Y(Fe 0.75 Al 0.25 ) 2 [158].
© IOP Publishing.
Reproduced with permission.
All rights reserved
magnetism is in fact a ferrimagnet. For RE 6 Fe 13 X compounds the comparison of
magnetic investigations with high field Mössbauer results it is shown that even in the
highest applied fields the spin moments are canted. In Fe pnictides crystallographically only one Fe site is present, which should lead to only one simple Mössbauer
spectrum, which is indeed found in zero field measurements. With the application
of an external field, spectra become so complex, that they cannot be explained by
only one subspectrum. This is only one example that the external field opens a new
window for elucidation of real magnetic ground states, which are not visible without
field. In the last example the magnetic behaviour of spin glasses is discussed. After