Related papers: What will be the maximum Tc in the iron-based supe…
We present a brief review of some recent work on the problem of highest achievable temperature of superconducting transition $T_c$ in electron-phonon systems. The discovery of record-breaking values of $T_c$ in quite a number of hydrides…
There is an ongoing debate about the relative importance of structural change versus doping charge carriers on the mechanism of superconductivity in Fe-based materials. Elucidating this issue is a major challenge since it would require a…
The discovery of superconductivity (SC) with a transition temperature, Tc, up to 65K in single-layer FeSe (bulk Tc =8K) films grown on SrTiO3 substrates has attracted special attention to Fe-based thin films. The high Tc is a consequence of…
The electric transport properties of superconducting FeSe0.3Te0.7/Au c-axis (S/N) junctions, fabricated by using Pulsed Laser Deposition technique, have been investigated in the temperature range of 2 K to the superconducting transition…
Predicting the transition temperature, Tc, of a superconductor from Periodic Table normal state properties is regarded as one of the grand challenges of superconductivity. By studying the correlations of Periodic Table properties with known…
The highest superconducting temperature T$_c$ observed in any elemental metal (Li with T$_c$ ~ 20 K at pressure P ~ 40 GPa) is shown to arise from critical (formally divergent) electron-phonon coupling to the transverse T$_1$ phonon branch…
We investigated pressure effects on transition temperature (Tc) of the new iron-based superconductor K0.8Fe2Se2 using a BeCu/NiCrAl hybrid-type clamped piston-cylinder cell. The Tc(onset) was 33K at 0.85 GPa. With increasing pressure,…
The pressure dependence of superconducting transition temperature $T_{\rm c}$ has been investigated through the DC magnetic measurements for FeSe$_{0.8}$ and FeSe$_{1.0}$. For both samples, with increasing pressure $P$, the $T_{\rm…
Recently, the superconductors' community has witnessed an unsettled debate regarding whether iron-based superconductors, in particular FeSe and FeSe$_{1-x}$S$_x$, are in the Bardeen-Cooper-Shrieffer (BCS) - Bose-Einstein condensation (BEC)…
Up to now, there have been two material families, the cuprates and the iron-based compounds with high-temperature superconductivity (HTSC). An essential open question is whether the two classes of materials share the same essential physics.…
Since the discovery of high temperature superconductivity in iron pnictides in early 2008, many iron-based superconductors with different structures have been discovered, with the highest transition temperature to date being 57 K. By the…
The full H-T phase diagram in the nematic superconductor FeSe is mapped out using specific-heat and thermal-expansion measurements down to 0.7 K and up to 30 T for both field directions. A clear thermodynamic signal of an underlying…
We have established a plot of the anion height dependence of Tc for the typical Fe-based superconductors. The plot appeared a symmetric curve with a peak around 1.38 A. Both data at ambient pressure and under high pressure obeyed the unique…
The surprising discovery of superconductivity in layered iron-based materials, with transition temperatures climbing as high as 55 K, has lead to thousands of publications on this subject over the past two years. While there is general…
We have investigated uniaxial and hydrostatic pressure effects on superconductivity in Fe1.07Te0.88S0.12 through magnetic-susceptibility measurements down to 1.8 K. The superconducting transition temperature Tc is enhanced by out-of-plane…
The theoretical maximum critical temperature ($T_c$) for conventional superconductors at ambient pressure remains a fundamental question in condensed matter physics. Through analysis of electron-phonon calculations for over 20,000 metals,…
We demonstrate the successful fabrication on CaF$_2$ substrates of FeSe$_{1-x}$Te$_{x}$ films with $0 \le x \le 1$, including the region of $0.1 \le x \le 0.4$, which is well known to be the "phase-separation region", via pulsed laser…
Searching for superconducting materials with high transition temperature (TC) is one of the most exciting and challenging fields in physics and materials science. Although superconductivity has been discovered for more than 100 years, the…
A wide variety of superconducting oxides are used to test a general model of high pressure induced transition temperature (T c) changes. The T c 's vary from a low of 24 K to a high of 164 K. Although the model is capable of predicting both…
The ternary iron arsenide BaFe2As2 becomes superconducting by hole doping, which was achieved by partial substitution of the barium site with potassium. We have discovered bulk superconductivity up to Tc = 38 K in (Ba1-xKx)Fe2As2 with x =…