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Title: Understanding the mechanisms of amorphous creep through molecular simulation

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Journal Article: Published Article
Journal Name:
Proceedings of the National Academy of Sciences of the United States of America
Additional Journal Information:
Journal Volume: 114; Journal Issue: 52; Related Information: CHORUS Timestamp: 2018-01-12 16:01:06; Journal ID: ISSN 0027-8424
Proceedings of the National Academy of Sciences
Country of Publication:
United States

Citation Formats

Cao, Penghui, Short, Michael P., and Yip, Sidney. Understanding the mechanisms of amorphous creep through molecular simulation. United States: N. p., 2017. Web. doi:10.1073/pnas.1708618114.
Cao, Penghui, Short, Michael P., & Yip, Sidney. Understanding the mechanisms of amorphous creep through molecular simulation. United States. doi:10.1073/pnas.1708618114.
Cao, Penghui, Short, Michael P., and Yip, Sidney. 2017. "Understanding the mechanisms of amorphous creep through molecular simulation". United States. doi:10.1073/pnas.1708618114.
title = {Understanding the mechanisms of amorphous creep through molecular simulation},
author = {Cao, Penghui and Short, Michael P. and Yip, Sidney},
abstractNote = {},
doi = {10.1073/pnas.1708618114},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
number = 52,
volume = 114,
place = {United States},
year = 2017,
month =

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  • Iron-based amorphous and nano-crystalline alloys have attracted a growing interest due to their potential in the application of magnetic coil production. However, fundamental understanding of the nano-crystallization mechanisms and magnetic features in the amorphous structure are still lack of knowledge. In the present work, we performed ab initio molecular dynamics simulation to clarify the ionic and electronic structure in atomic scale, and to derive the origin of the good magnetic property of Fe{sub 85}Si{sub 2}B{sub 8}P{sub 4}Cu{sub 1} amorphous alloy. The simulation gave a direct evidence of the Cu-P bonding preference in the amorphous alloy, which may promote nucleation inmore » nano-crystallization process. On the other hand, the electron transfer and the band/orbital features in the amorphous alloy suggests that alloying elements with large electronegativity and the potential to expand Fe disordered matrix are preferred for enhancing the magnetization.« less
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  • The doping mechanism in organic-semiconductor films has been quantitatively studied via ultrahigh-sensitivity ultraviolet photoelectron spectroscopy of N,N-bis(1-naphthyl)-N,N-diphenyl-1,1-biphenyl-4,4-diamine (α-NPD) films doped with hexaazatriphenylene-hexacarbonitrile [HAT(CN){sub 6}]. We observed that HOMO of α-NPD shifts to the Fermi level (E{sub F}) in two different rates with the doping concentration of HAT(CN){sub 6}, but HOMO distributions of both pristine and doped amorphous α-NPD films are excellently approximated with a same Gaussian distribution without exponential tail states over ∼5 × 10{sup 18} cm{sup −3} eV{sup −1}. From the theoretical simulation of the HAT(CN){sub 6}-concentration dependence of the HOMO in doped films, we show that the passivation of Gaussian-distributedmore » hole traps, which peak at 1.1 eV above the HOMO onset, occurs at ultralow doping [HAT(CN){sub 6} molecular ratio (MR) < 0.01], leading to a strong HOMO shift of ∼0.40 eV towards E{sub F}, and MR dependence of HOMO changes abruptly at MR ∼ 0.01 to a weaker dependence for MR > 0.01 due to future of the dopant acceptor level.« less
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