Related papers: What will be the maximum Tc in the iron-based supe…
The study of the iron-based superconductor FeSe has blossomed with the availability of high quality single crystals, obtained through flux/vapor-transport growth techniques below the structural transformation temperature of its tetragonal…
A fundamental issue concerning iron-based superconductivity is the roles of electronic nematicity and magnetism in realising high transition temperature ($T_{\rm c}$). To address this issue, FeSe is a key material, as it exhibits a unique…
Energetic ion irradiation usually decreases superconducting critical temperature(Tc), with the few exceptions involving increases up to a few K only. However, our recent 2.5X10^15 Ar/cm2 irradiations by 1.5 MeV Ar6+ enhanced Tc of the…
A theory of high temperature superconductivity based on the combination of the fermion-condensation quantum phase transition and the conventional theory of superconductivity is presented. This theory describes maximum values of the…
Pressure plays an essential role in the induction1 and control2,3 of superconductivity in iron-based superconductors. Substitution of a smaller rare-earth ion for the bigger one to simulate the pressure effects has surprisingly raised the…
A new hight Tc Fe-based compound system, AFe2As2 with A = K, Cs, K/Sr and Cs/Sr has been found. Through electron-doping, Tc of the A = K and Cs compounds rises to ~37 K, and finally enter a spin-density-wave state (SDW) through further…
The latest discovery of high temperature superconductivity signature in single-layer FeSe is significant because it is possible to break the superconducting critical temperature ceiling (maximum Tc~55 K) that has been stagnant since the…
In contrast to bulk FeSe superconductor, heavily electron-doped FeSe-derived superconductors show relatively high Tc without hole Fermi surfaces and nodal superconducting gap structure, which pose great challenges on pairing theories in the…
It is demonstrated that the transition temperature (Tc) of high-Tc superconductors is determined by their layered crystal structure, bond lengths, valency properties of the ions, and Coulomb coupling between electronic bands in adjacent,…
Exploration of new superconductors has always been one of the research directions in condensed matter physics. We report here a new layered heterostructure of [(Fe,Al)(OH)2][FeSe]1.2, which is synthesized by the hydrothermal ion-exchange…
The recently discovered iron arsenide superconductors, which display superconducting transition temperatures as high as 55 K, appear to share a number of general features with high-Tc cuprates, including proximity to a magnetically ordered…
A large and high-quality single crystal (Li0.84Fe0.16)OHFe0.98Se, the optimal superconductor of newly reported (Li1-xFex)OHFe1-ySe system, has been successfully synthesized via a hydrothermal ion-exchange technique. The superconducting…
Tetragonal FeSe is a superconductor with a transition temperature Tc of 8 K and shows a huge enhancement of Tc with applying pressure. Tetragonal FeTe has a structure very analogous to superconducting FeSe, but does not show superconducting…
We report the pressure dependences of the superconducting transition temperature (T_c) in several perovskite-type Fe-based superconductors through the resistivity measurements up to ~4 GPa. In Ca_4(Mg,Ti)_3Fe_2As_2O_y with the highest T_c…
We report here that a new superconducting phase with much higher Tc has been found in K intercalated FeSe compound with excess Fe. We successfully grew crystals by precisely controlling the starting amount of Fe. Besides the superconducting…
Taking cue from the increase in the superconducting transition temperature (Tc) of Fe1+xSe via nominal (2 wt%) substitution of Cr instead of excess Fe, we have now extended our study with nominal substitution (<=5 wt%) with other transition…
Recently, interface has been employed to enhance superconductivity in the single-layer FeSe films grown on SrTiO3(001)(STO) with a possible Tc of ~ 80 K, which is nearly ten times of the Tc of bulk FeSe and is above the Tc record of 56 K…
We present a theoretical ab-initio approach that allows us to explicitly calculate the superconducting transition temperatures (Tc) of the iron-based superconductors of LaFeAsO1-xFx, SmFeAsO1-xFx, NdFeAsO1-xFx, Ba1-xKxFe2As2, FeSe and…
Recent experiments have shown that, in agreement with previous theoretical predictions, superconductivity in metallic nanostructures can be enhanced with respect to the bulk limit. Motivated by these results we study finite size effects…
We investigate the high-pressure phase of the iron-based superconductor FeSe$_{0.89}$S$_{0.11}$ using transport and tunnel diode oscillator studies. We construct detailed pressure-temperature phase diagrams that indicate that outside of the…