Electrostatic hyperfine interactions in Y(Fe, Al)2

Room temperature 57Fe Moessbauer and X-ray diffraction measurements are reported for Y(Fesub(x)Alsub(1-x))2, 0.1 <= x < 0.9. For x <= 0.65 broadened and on the Al-rich side structurized Bragg-peaks are observed. The asymmetry of the quadrupole split Moessbauer spectra depends on x. Whereas two different slopes are obtained for the concentration dependence of the mean quadrupole splitting on the Al- and the Fe-rich side, the isomer shift exhibits a smooth dependence on x, which can be correlated to the change in volume caused by the Al substitution. (Auth.)