Fe-vacancy ordered Fe4Se5: The insulating parent phase of FeSe superconductor

Keng-Yu Yeh; Yan-Rai Chen; Tung-Sheng Lo; Phillip M. Wu; Ming-Jye Wang; Kuei-Shu Chang-Liao; Maw-Kuen Wu

Fe-vacancy ordered Fe4Se5: The insulating parent phase of FeSe superconductor

Superconductivity 2020-10-27 v1

Authors: Keng-Yu Yeh , Yan-Rai Chen , Tung-Sheng Lo , Phillip M. Wu , Ming-Jye Wang , Kuei-Shu Chang-Liao , Maw-Kuen Wu

Abstract

We have carried out a detailed study to investigate the existence of an insulating parent phase for FeSe superconductor. The insulating Fe4Se5 with specific Fe-vacancy order shows a 3D-Mott variable range hopping behavior with a Verwey-like electronic correlation at around 45 K. The application of the RTA process at 450 celcius degree results in the destruction of Fe-vacancy order and induces more electron carriers by increasing the Fe3+ valence state. Superconductivity emerges with Tc ~ 8K without changing the chemical stoichiometry of the sample after the RTA process by resulting in the addition of extra carriers in favor of superconductivity.

Keywords

Fe4Se5 FeSe superconductor insulating parent phase Fe-vacancy order Mott variable range hopping RTA process

Cite

@article{arxiv.2010.13330,
  title  = {Fe-vacancy ordered Fe4Se5: The insulating parent phase of FeSe superconductor},
  author = {Keng-Yu Yeh and Yan-Rai Chen and Tung-Sheng Lo and Phillip M. Wu and Ming-Jye Wang and Kuei-Shu Chang-Liao and Maw-Kuen Wu},
  journal= {arXiv preprint arXiv:2010.13330},
  year   = {2020}
}

Comments

20 pages, 9 figures, 2 tables

Fe-vacancy ordered Fe4Se5: The insulating parent phase of FeSe superconductor

Abstract

Keywords

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