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Time-dependent density-functional theory molecular-dynamics study on amorphization of Sc-Sb-Te alloy under optical excitation
被引:39
作者:
Wang, Xue-Peng
[1
]
Li, Xian-Bin
[1
]
Chen, Nian-Ke
[1
]
Bang, Junhyeok
[2
]
Nelson, Ryky
[3
]
Ertural, Christina
[3
]
Dronskowski, Richard
[3
,4
]
Sun, Hong-Bo
[1
,5
]
Zhang, Shengbai
[6
]
机构:
[1] Jilin Univ, Coll Elect Sci & Engn, State Key Lab Integrated Optoelect, Changchun 130012, Peoples R China
[2] Chungbuk Natl Univ, Dept Phys, Chungbuk 28644, South Korea
[3] Rhein Westfal TH Aachen, Inst Inorgan Chem, D-52056 Aachen, Germany
[4] Shenzhen Polytech, Hoffmann Inst Adv Mat, Shenzhen 518055, Peoples R China
[5] Tsinghua Univ, State Key Lab Precis Measurement Technol & Instru, Dept Precis Instrument, Beijing 100084, Peoples R China
[6] Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 USA
基金:
新加坡国家研究基金会;
中国国家自然科学基金;
关键词:
PHASE-CHANGE MATERIALS;
PLANE-WAVE;
MEMORY;
CRYSTALLIZATION;
TRANSITIONS;
FILMS;
COHP;
D O I:
10.1038/s41524-020-0303-z
中图分类号:
O64 [物理化学(理论化学)、化学物理学];
学科分类号:
070304 ;
081704 ;
摘要:
Recently, all-optical memory and optical-computation properties of phase-change materials are receiving intensive attention. Because writing/erasing information in these devices is usually achieved by laser pulses, the interaction between the laser and the phase-change materials becomes a key issue for such new applications. In this work, by a time-dependent density-functional theory molecular-dynamics study, the physics underlying the optical excitation induced amorphization of Sc-Sb-Te is revealed, which goes back to superatom-like Sc-centered structural motifs. These motifs are found to be still robust under the excitation. A selected occupation of the Sc d-t(2g) orbitals (as a result of optical excitation) leads to a significant change of Sc-centered bond angles. In addition, the especially weak Sb-Te bonds next to the Sc motifs are further diminished by excitations. Therefore, the Sc-centered motifs can promote breaking, switching, and reforming of the surrounding Sb-Te network and, therefore, facilitate the amorphization of Sc-Sb-Te. The study shows the unique role of Sc-centered motifs in optically induced phase transition, and displays potential applications of Sc-Sb-Te alloys in optical memory/computation.
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