Superconducting transition temperatures in electronic and magnetic phase diagram of a superconductor, Sr2VFeAsO3−δ

Yujiro Tojo, Taizo Shibuya, Tetsuro Nakamura, Koichiro Shoji, Hirotaka Fujioka, Masanori Matoba, Shintaro Yasui, Mitsuru Itoh, Soshi Iimura, Hidenori Hiramatsu, Hideo Hosono, Shigeto Hirai, Wendy Mao, Shinji Kitao, Makoto Seto, Yoichi Kamihara

Research output: Contribution to journalArticlepeer-review

Abstract

We unveil magnetic phases and superconducting transition temperatures (Tc) in an iron-based superconductor with a thick-blocking layer of a perovskite-related transition metal oxide, Sr2VFeAsO3-δ (21113V). 21113V exhibits a superconducting phase in 0.031 ≤ δ ≤ 0.145 at temperatures (T) < 37.1 K. Antiferromagnetic (AFM) iron sublattice are observed in 0.267 ≤ δ ≤ 0 0.664. A mixed valent vanadium exhibits a dominant AFM phase in 0.031 ≤ δ ≤ 0 0.088, while a partial ferrimagnetic (Ferri.) phase of the vanadium appears in 0.124 ≤ δ ≤ 0 0.664. The partial Ferri. phase becomes the most dominant for δ~0.267, in which the Fe shows AFM phase at T < 20 K. A volume fraction of the superconducting phase is suppressed by increasing of spontaneous magnetic moments due to the partial Ferri. vanadium; i.e the magnetic phase of the vanadium dominates superconductivity in 21113V. The Tc - δ curve shows two maxima. The lower maximum of Tc are observed for δ = 0.073. It is noted that the highest Tc of 21113V appears for δ = 0.145, which exists in a phase boundary between AFM and the partial Ferri. phases of the vanadium. 21113V is a platform to verify new mechanism for enhancing Tc in iron-based superconductors.

Original languageEnglish
JournalUnknown Journal
Publication statusPublished - 2018 Feb 12

Keywords

  • Antiferromagnetism
  • Iron-based superconductors
  • Layered perovskite-type oxide
  • Oxygen deficiency
  • Phase diagram
  • SrVFeAsO

ASJC Scopus subject areas

  • General

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