Synthesis, characterization, Hall effect and THz conductivity of epitaxial thin films of Fe chalcogenide superconductors

Maeda, Akiko; Nabeshima, Fuyuki; Takahashi, Hideyuki; Okada, Tatsunori; Imai, Yoshio; Tsukada, I.; Hanawa, Masafumi; Komiya, Seiki; Ichinose, Ataru

doi:10.1016/j.apsusc.2014.02.124

Cited by 24 publications

(28 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Data from literature are added for comparison; in these cases, the critical temperature is the one declared in the original papers. The data come from PCARS [3], STS [4,6,10], ARPES [2,9], tunnel spectroscopy [5], specific heat [35] and THz spectroscopy [32].…”

Section: Resultsmentioning

confidence: 99%

Point-contact Andreev-reflection spectroscopy in Fe(Te,Se) films: multiband superconductivity and electron-boson coupling

Daghero¹,

Pecchio²,

Ummarino³

et al. 2014

Supercond. Sci. Technol.

View full text Add to dashboard Cite

We report on a study of the superconducting order parameter in Fe(Te1−xSex) thin films (with different Se contents: x = 0.3, 0.4, 0.5) by means of point-contact Andreev-reflection spectroscopy (PCARS). The PCARS spectra show reproducible evidence of multiple structures, namely two clear conductance maxima associated to a superconducting gap of amplitude ∆E ≃ 2.75kBTc and additional shoulders at higher energy that, as we show, are the signature of the strong interaction of charge carriers with a bosonic mode whose characteristic energy coincides with the spin-resonance energy. The details of some PCARS spectra at low energy suggest the presence of a smaller and not easily discernible gap of amplitude ∆H ≃ 1.75kBTc. The existence of this gap and its amplitude are confirmed by PCARS measurements in Fe(Te1−xSex) single crystals. The values of the two gaps ∆E and ∆H, once plotted as a function of the local critical temperature T A c , turn out to be in perfect agreement with the results obtained by various experimental techniques reported in literature.

show abstract

Section: Resultsmentioning

confidence: 99%

Point-contact Andreev-reflection spectroscopy in Fe(Te,Se) films: multiband superconductivity and electron-boson coupling

Daghero¹,

Pecchio²,

Ummarino³

et al. 2014

Supercond. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…The increase in R H may be related to the nematicity in FeSe. [28][29][30] In contrast, it has been reported that the sign of R H for FeSe single crystals is negative at low temperatures. 31,32) The origin of the difference in R H can be explained by the difference in the band structures between single crystals and films on CaF 2 .…”

mentioning

confidence: 91%

Investigation of Transport Properties for FeSe₁₋_xTe_x Thin Films under Magnetic Fields

et al. 2016

View full text Add to dashboard Cite

We investigated the transport properties under magnetic fields of up to 9 T for FeSe 1−x Te x thin films on CaF 2 . Measurements of the temperature dependence of the electrical resistivity revealed that for x = 0.2-0.4, where T c is the highest, the width of the superconducting transition increased with increasing magnetic field, while the width was almost the same with increasing magnetic field for x = 0-0.1. In addition, the temperature dependence of the Hall coefficient drastically changed between x = 0.1 and 0.2 at low temperatures. These results indicate that clear differences in the nature of the superconductivity and electronic structure exist between x = 0-0.1 and x ≥ 0.2.

show abstract

“…The complete phase diagram that we present provides a novel perspective for the mechanism of superconductivity of this material. The data for x = 0 and 0.5 presented in (a)-(e) are cited from our previous papers [4,14].…”

mentioning

confidence: 99%

Suppression of phase separation and giant enhancement of superconducting transition temperature in FeSe _{1−
x} Te _x thin films

Imai

Sawada

Nabeshima

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

We demonstrate the successful fabrication on CaF2 substrates of FeSe1−xTex films with 0≤x≤1, including the region of 0.1≤x≤0.4, which is well known to be the “phase-separation region,” via pulsed laser deposition that is a thermodynamically nonequilibrium method. In the resulting films, we observe a giant enhancement of the superconducting transition temperature, Tc, in the region of 0.1≤x≤0.4: The maximum value reaches 23 K, which is ∼1.5 times as large as the values reported for bulk samples of FeSe1−xTex. We present a complete phase diagram of FeSe1−xTex films. Surprisingly, a sudden suppression of Tc is observed at 0.1<x<0.2, whereas Tc increases with decreasing x for 0.2≤x<1. Namely, there is a clear difference between superconductivity realized in x=0−0.1 and in x≥0.2. To obtain a film of FeSe1−xTex with high Tc, the controls of the Te content x and the in-plane lattice strain are found to be key factors.

show abstract

Synthesis, characterization, Hall effect and THz conductivity of epitaxial thin films of Fe chalcogenide superconductors

Cited by 24 publications

References 47 publications

Point-contact Andreev-reflection spectroscopy in Fe(Te,Se) films: multiband superconductivity and electron-boson coupling

Point-contact Andreev-reflection spectroscopy in Fe(Te,Se) films: multiband superconductivity and electron-boson coupling

Investigation of Transport Properties for FeSe₁₋_xTe_x Thin Films under Magnetic Fields

Suppression of phase separation and giant enhancement of superconducting transition temperature in FeSe _{1−
x} Te _x thin films

Contact Info

Product

Resources

About

Synthesis, characterization, Hall effect and THz conductivity of epitaxial thin films of Fe chalcogenide superconductors

Cited by 24 publications

References 47 publications

Point-contact Andreev-reflection spectroscopy in Fe(Te,Se) films: multiband superconductivity and electron-boson coupling

Point-contact Andreev-reflection spectroscopy in Fe(Te,Se) films: multiband superconductivity and electron-boson coupling

Investigation of Transport Properties for FeSe1−xTex Thin Films under Magnetic Fields

Suppression of phase separation and giant enhancement of superconducting transition temperature in FeSe 1− x Te x thin films

Contact Info

Product

Resources

About

Investigation of Transport Properties for FeSe₁₋_xTe_x Thin Films under Magnetic Fields

Suppression of phase separation and giant enhancement of superconducting transition temperature in FeSe _{1−
x} Te _x thin films