X-Ray Investigation of Crystallization of the Metallic Glass Fe40Ni40B20.

The metallic glass Fe//4//0Ni//4//0B//2//0 was investigated by different methods of X-ray wide angle scattering in the as-quenched state, partially crystallized, and fully crystallized. The Fourier-transformation of the intensity function gave a coordination number for the metal atoms of 11. 2 plus or minus 0. 2. This number is practically independent of the state of crystallization although the correlation function is very sensitive to structural changes in the second and higher maxima. After a temperature treatment at 350 degree C, a cubic face-centered iron-nickel phase crystallizes in a glassy matrix. The iron-to-nickel ratio in these crystallites differs, however, from the stoichiometric value. The temperature dependence of crystallite size, stacking faults, fluctuation of lattice constants, and chemical composition is discussed.