Microwave surface impedance measurements of LiFeAs, LiFe(As,P) and FeSe1-xTex single crystals

Y. Imai, H. Takahashi, T. Okada, T. Yoshinaka, S. Komiya, K. Kitagawa, K. Matsubayashi, I. Tsukada, Y. Uwatoko, A. Maeda

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


We study microwave surface impedance measurements of LiFeAs, LiFe(As,P) and FeSe1-xTex single crystals. The in-plane penetration depths of LiFeAs and LiFe(As,P) depend on temperature exponentially at low temperatures, which is a strong indication that these two materials have the nodeless superconducting gap. The temperature dependence of the superfluid density indicates that LiFeAs and LiFe(As,P) are multi-gap superconductors with at least two isotropic gaps. In FeSe1-xTex, on the other hand, the quadratic temperature dependence of the in-plane penetration depth appears, which indicates the existence of some sort of quasiparticle excitations. In addtion, the real part of the microwave conductivity exhibits a large enhancement below Tc in all three materials, which results from the increase of the quasiparticle relaxation time, τ, below Tc.

Original languageEnglish
Pages (from-to)630-633
Number of pages4
JournalPhysica C: Superconductivity and its applications
Issue number21-22
Publication statusPublished - 2011 Nov
Externally publishedYes


  • FeSe Te
  • LiFeAs
  • Microwave surface impedance
  • Penetration depth

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Energy Engineering and Power Technology
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Microwave surface impedance measurements of LiFeAs, LiFe(As,P) and FeSe<sub>1-x</sub>Te<sub>x</sub> single crystals'. Together they form a unique fingerprint.

Cite this