Study of the local structure of CuZr amorphous alloys by exafs. Effect of a structural relaxation

A structural investigation of Cu_xZr_1?x amorphous alloys has been made using EXAFS (x = 0.33, 0.46, 0.60). The partial radial distribution functions of the first shell of neighbours were derived from the study of the Cu and Zr K absorption edges. The distribution of the CuCu pairs remains almost constant in the whole range of concentration while the distribution of the unlike atom pairs varies drastically, becoming more asymmetric with increasing Cu content. In the meantime, the chemical ordering increases.A study of structural relaxation has been done for the Cu₆₀Zr₄₀ and Cu₄₆Zr₅₄ glasses by DTA and EXAFS. An additional endothermic phenomenon appears at T_g on DTA curves after annealing. No drastic change was observed by EXAFS. A slight increase of the spectrum was however obtained on the Cu edge for Cu₆₀Zr₄₀.