Jiang, JZ (reprint author), Zhejiang Univ, Sch Mat Sci & Engn, Int Ctr New Struct Mat, Hangzhou 310027, Peoples R China.
; Jiang, JZ (reprint author), Zhejiang Univ, Sch Mat Sci & Engn, State Key Lab Silicon Mat, Lab New Struct Mat, Hangzhou 310027, Peoples R China.
文章类型:
期刊论文
英文摘要:
In pressure-induced reversible structural transitions, the term "reversible" refers to the recovery of the virgin structure in a material upon complete decompression. Pressure-induced amorphous-to-crystalline transitions have been claimed to be reversible, but evidence that amorphous material recovers its virgin amorphous structure upon complete depressurization has been lacking. In amorphous As2Se3 (a-As2Se3) chalcogenide, however, we report a novel reversible amorphous-to-crystalline transition that provides compelling experimental evidence that upon complete decompression, the recovered amorphous phase is structurally the same as that of the virgin (as-cast) amorphous phase. Combining the experimental results with ab initio molecular dynamics simulations, we elucidate that the amorphization ismediated by a surplus of total free energy in the high-pressure face-centered cubic phase as compared to the virgin amorphous phase and that the structural recovery to the virgin amorphous phase is a consequence of an enhancement in covalent bonding character over interlayer forces upon complete decompression. Furthermore, we observed a two-dimensional to three-dimensional network transition under compression and its reversibility upon decompression.
