Related papers: Two new parent compounds for FeSe-based supercondu…

Superconductivity under pressure in FeSe ($T_{\rm c}$$\sim$7.5 K) has been investigated using single-crystal specimens through the measurements of DC magnetization and electrical resistivity. A characteristic three-step increase in $T_{\rm…

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.…

We report the effect of applied pressures on magnetic and superconducting order in single crystals of the aliovalent La-doped iron pnictide material Ca$_{1-x}$La$_{x}$Fe$_{2}$As$_{2}$. Using electrical transport, elastic neutron scattering…

Structure and composition of iron chalcogenides have a delicate relationship with magnetism and superconductivity. In this report we investigate the iron sulfide layered tetragonal phase (t-FeS), and compare with three-dimensional hexagonal…

New iron selenide superconductors by intercalating smaller-sized alkali metals (Li, Na) and alkaline earths using high-temperature routes have been pursued ever since the discovery of superconductivity at about 30 K in KFe2Se2, but all have…

The Ca10(PtnAs8)(Fe2As2)5 (n=3,4) compounds are a new type of iron pnictide superconductors whose structures consist of stacking Ca-PtnAs8-Ca-Fe2As2 layers in a unit cell. When n=3 (the 10-3-8 phase), the undoped compound is an…

The recent discovery of iron ferropnictide superconductors has received intensive concerns on magnetic involved superconductors. Prominent features of ferropnictide superconductors are becoming apparent: the parent compounds exhibit…

Fe-based superconductors were discovered in 2008. This discovery with T$_c$ values up to 56 K, generated a new belief in the field of superconductivity. Till its discovery, high temperature superconductivity in cuprates, created a prejudice…

The nature of metallicity and the level of electronic correlations in the antiferromagnetically ordered parent compounds are two important open issues for the iron-based superconductivity. We perform a temperature-dependent angle-resolved…

Here we establish a combined electronic phase diagram of isoelectronic FeSe1-xSx (0.19 > x > 0.0) and FeSe1-yTey (0.04 < y < 1.0) single crystals. The FeSe1-yTey crystals with y = 0.04 - 0.30 are grown by a hydrothermal ion-deintercalation…

The discovery of cuprate high Tc superconductors has inspired searching for unconventional su- perconductors in magnetic materials. A successful recipe has been to suppress long-range order in a magnetic parent compound by doping or high…

The superconducting state of iron pnictides and chalcogenides exists at the border of antiferromagnetic order. Consequently, these materials could provide clues about the relationship between magnetism and unconventional superconductivity.…

Iron Selenide, Fe1.01Se, the layered parent compound of the recently discovered superconducting arsenide family, has previously been shown to be non magnetic and superconducting with a critical temperature of 8 K. Here we show that copper…

Superconductivity in iron selenides has experienced a rapid growth, but not without major inconsistencies in the reported properties. For alkali-intercalated iron selenides, even the structure of the superconducting phase is a subject of…

We investigate the electronic and magnetic structures of the 122 (AM$_2$B$_2$) hexagonal transition-metal pnictides with A=(Sr, Ca), M=(Cr, Mn, Fe, Co, Ni) and B=(As, P, Sb). It is found that the family of materials share critical…

A review of the magnetism in the parent compounds of the iron-based superconductors is given based on the transmission Moessbauer spectroscopy of 57Fe and 151Eu. It was found that the 3d magnetism is of the itinerant character with varying…

The recently discovered LaFe2As2 superconducting compound, member of the 122 family of iron pnictide superconductors, becomes superconducting below Tc=13K, yet its nominal doping apparently places it in the extreme overdoped limit, where…

The interplay of structural and electronic phases in iron-based superconductors is a central theme in the search for the superconducting pairing mechanism. While electronic nematicity, defined as the breaking of four-fold symmetry triggered…

In this letter we show that superconducting Fe1.01Se undergoes a structural transition at 90 K from a tetragonal to an orthorhombic phase but that non-superconducting Fe1.03Se does not. Further, high resolution electron microscopy study at…

Iron selenide (FeSe) - the structurally simplest iron-based superconductor, has attracted tremendous interest in the past years. While the transition temperature (Tc) of bulk FeSe is $\sim$ 8 K, it can be significantly enhanced to 40 - 50 K…