Neutron diffraction and reverse Monte Carlo study of bulk amorphous Ga₃₈Sb₃₈Ge₂₄ alloys

The structure of bulk amorphous Ga₃₈Sb₃₈Ge₂₄ alloy produced by thermobaric treatment was studied at 100 K by neutron diffraction. The Fourier transformation of the measured structure factor clearly shows that two nearest-neighbor distances exist in the alloy. The results are compared to the ones obtained for the similarly produced amorphous GaSb, studied earlier. The analysis of the data reveals that the amorphous Ga₃₈Sb₃₈Ge₂₄ alloy is homogenous. The average nearest-neighbor coordination number obtained, 4.25, is greater than 4, indicating that the tetrahedral arrangements in the sample are distorted. Reverse Monte Carlo simulations were carried out using the measured structure factor of both alloys. It is shown that the degree of chemical disorder in both amorphous alloys is large.