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Competitive Phase Separation to Controllable Crystallization in 80 GeS 2 ·20 In 2 S 3 Chalcogenide Glass
Author(s) -
Li Zhuobin,
Lin Changgui,
Nie Qiuhua,
Dai Shixun
Publication year - 2013
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.12088
Subject(s) - crystallization , differential scanning calorimetry , precipitation , materials science , phase (matter) , analytical chemistry (journal) , activation energy , crystal (programming language) , elongation , crystallography , mineralogy , chemical engineering , thermodynamics , chemistry , composite material , chromatography , physics , organic chemistry , ultimate tensile strength , meteorology , computer science , programming language , engineering
Glass–ceramics of 80 GeS 2 ·20 In 2 S 3 were fabricated by heat‐treating the base glass at 402°C ( T g + 30°C) for different durations. The glass–ceramics exhibited some improved mechanical properties such as hardness and resistance to crack propagation, and meanwhile remained an excellent infrared ( IR ) transmission. The XRD and R aman results showed that only In 2 S 3 crystals were precipitated inside glassy matrix. The evolution of two crystallization peaks ( CP s) in differential scanning calorimeter ( DSC ) curves were studied with samples heat‐treated at 402°C for different durations. It was found that the precipitation of In 2 S 3 crystal phase is responsible for the low‐temperature (first) CP , whereas the high‐temperature (second) CP shifts to a higher temperature with the elongation of the heat‐treatment duration. The crystallization of the higher temperature phase was inhibited with the precipitation of In 2 S 3 . Furthermore, crystallization mechanism was investigated using the nonisothermal method. The computed results showed that strictly more energy (higher activation energy, E c ) is essential for the precipitation of the higher temperature phase, which is in accordance with the DSC study of crystallized samples. More noticeable, the crystallization rate constant ( K ) value of 6.639 × 10 −8 s −1 for the second CP is ~ 5 orders of magnitude smaller than that of the In 2 S 3 phase, and this significant difference makes the crystallization of higher temperature crystal phase very hard. Consequently, controllable crystallization of 80 GeS 2 ·20 In 2 S 3 chalcogenide glass–ceramics with sole In 2 S 3 crystallites can be achieved easily.