422
M. Reissner
Fig. 8.42 Magnetic phase diagram of Y(Fe x Al 1−x ) 2 , T c Curie temperature, T M maximum temperature, T A temperature where magnetic hyperfine splitting vanishes, T P temperature above which
magnetization curves are linear. Adapted from [143]
magnetization curves are still present, extends to 7 times T f . Below T M irreversibilities, time dependence and history effects are present. This all indicates cluster glass
behaviour for x < 0.78. One point left open by these investigations is the question
concerning the stability of the Fe moment. The only mildly concentration dependent
mean effective moment points to a non-vanishing Fe moment that stays relatively
constant over the entire concentration range, whereas the Mössbauer investigations
indicate a strong influence of local environment on electrostatic and magnetic hyperfine interactions. Therefore the question arise, whether or not the iron moment also
depends on the local coordination. There were some contradicting results in literature. Non spin-polarized band-structure calculations on Y(Fe,Al) 2 have shown a
M. Reissner
Fig. 8.42 Magnetic phase diagram of Y(Fe x Al 1−x ) 2 , T c Curie temperature, T M maximum temperature, T A temperature where magnetic hyperfine splitting vanishes, T P temperature above which
magnetization curves are linear. Adapted from [143]
magnetization curves are still present, extends to 7 times T f . Below T M irreversibilities, time dependence and history effects are present. This all indicates cluster glass
behaviour for x < 0.78. One point left open by these investigations is the question
concerning the stability of the Fe moment. The only mildly concentration dependent
mean effective moment points to a non-vanishing Fe moment that stays relatively
constant over the entire concentration range, whereas the Mössbauer investigations
indicate a strong influence of local environment on electrostatic and magnetic hyperfine interactions. Therefore the question arise, whether or not the iron moment also
depends on the local coordination. There were some contradicting results in literature. Non spin-polarized band-structure calculations on Y(Fe,Al) 2 have shown a