EN
Structure and magnetic order of rapidly quenched (Fe_{1-x}Co_{x})_{79}Mo_8Cu_1B_{12} alloys is investigated by ^{57}Fe Mössbauer spectrometry in transmission geometry and by conversion electron Mössbauer spectrometry. The effect of heat treatment upon hyperfine interactions was studied as a function of Co contents (x = 0, 0.5). Magnetic dipole interactions developed in both alloys when sufficient number of ferromagnetic nanograins is created after heat treatment. The kinetics of crystallization was derived from in situ diffraction of synchrotron radiation. The progress of crystallization is different at both sides of the ribbon-shaped samples.