کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7990407 | 1516127 | 2018 | 9 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Pressure-induced isostructural phase transition and charge transfer in superconducting FeSe
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موضوعات مرتبط
مهندسی و علوم پایه
مهندسی مواد
فلزات و آلیاژها
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چکیده انگلیسی
We present extensive investigations of the crystallographic phase diagram and electronic properties of the Fe-based superconductor FeSe under extreme conditions (high pressure (HP) and low temperature (LT)) by synchrotron X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS). An isostructural phase transition (Tetragonal (T) âhigh-pressure Tetragonal (Tʹ)) is discovered in FeSe at â¼2.8â¯GPa based on the axial ratio c/a with finer pressure step as observed in Fe-As-based superconductor such as EuFe2As2. We also find a pressure-induced Tʹ â MnP-type phase transition at 7.6 GPa in FeSe, which is consistent with the documented pressure-induced high-spin â low-spin transition (â¼6-7 GPa). These results reveal the pressure-induced structural phase transition sequence in FeSe at room temperature to be T â Tʹ â Tʹ+MnP-type at pressures of 0-10.6 GPa, enriching the crystallographic phase diagram. The HPLT XRD data also indicate that a sluggish structural phase transition (Cmma â Pnma) begins at 7.5â¯GPa, and these two phases coexist up to 26.5â¯GPa. The HP X-ray absorption near-edge spectroscopy (XANES) measurement shows that Eo of Se experiences a pressure-induced shift to high energy, evidencing strongly charge transfer between Fe and Se under high pressure. Our results shed lights on the correlation between crystallographic/electronic structure and superconductivity in this material.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Alloys and Compounds - Volume 767, 30 October 2018, Pages 811-819
Journal: Journal of Alloys and Compounds - Volume 767, 30 October 2018, Pages 811-819
نویسندگان
Zhenhai Yu, Ming Xu, Zhipeng Yan, Hao Yan, Jinggeng Zhao, Umeshkumar Patel, Dale L. Brewe, Steve M. Heald, Jingyuan Ma, Yanfeng Guo, Ke Yang, Zhili Xiao, Lin Wang,