In this paper, the last glass-ceramics recently made from chalco-halide glasses is presented. Various glass-ceramics were obtained from compositions belonging to different systems such as Ge-(Sb/Ga)-(S/Se)-MX (MX: alkali halide). XRD experiments and SEM observations were performed to determine the crystallization mechanism in these chalcogenide glasses. While alkali halide such as CsCl is rejected from the glassy network in antimony based glasses leading to its crystallization, some gallium

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... d glasses present a quasi-arranged structure which tends to reach a higher stability by crystallizing as Ga4GeSe8 or Ga2Se3. Thus, the amount of alkali halides introduced in antimony based glasses limits the crystallization rate to 20% of the glassy matrix. Furthermore, the crystallization of gallium based phases having a refractive index close to the matrix one lowers the scatterings permitting to keep an excellent infrared transmittance with a crystallized proportion of about 40%.