Temperature-dependent hyperfine interactions in Fe2B.

Moessbauer absorption spectra have been observed for Fe2B from 290 to 1175 K. A change in the electric quadrupole interaction was observed from 460 to 480 K and interpreted as a result of the rotation of the easy axis of magnetization as a function of temperature. The effective magnetic hyperfine field is defined as a function of temperature. A discontinuity in the isomer shift of 0.018 (plus or minus 0.010) mm/sec was found across the ferromagnetic transition.