Related papers: (Sr_3Sc_2O_5)Fe_2As_2 as a possible parent compoun…

Magnetic properties of $M_{c}$Ta$_{2}$S$_{2}$C ($M$ = Fe, Co, Ni, Cu) have been studied using SQUID DC and AC magnetic susceptibility. In these systems magnetic $M^{2+}$ ions are intercalated into van der Waals gaps between adjacent S…

We synthesized new REO0.5F0.5BiS2 (RE: rare earth) superconductors with the high-entropy-alloy-type (HEA-type) REO blocking layers. According to the RE concentration and the RE ionic radius, the lattice constant of a systematically changed…

By using a hydrothermal method, we have successfully grown crystals of the newly discovered superconductor FeS, which has an isostructure of the iron based superconductor FeSe. The superconductivity appears at about 4.5K, as revealed by…

A new layered iron arsenide oxide (Fe2As2)(Ca5(Mg,Ti)4Oy) and its structural derivative were found in the Fe-As-Ca-Mg-Ti-O system. The crystal structure of (Fe2As2)(Ca5(Mg,Ti)4Oy) is identical to that of (Fe2As2)(Ca5(Sc,Ti)4Oy), which was…

In the family of the iron-based superconductors, the $RE$FeAsO-type compounds (with $RE$ being a rare-earth metal) exhibit the highest bulk superconducting transition temperatures ($T_{\mathrm{c}}$) up to $55\ \textrm{K}$ and thus hold the…

Ultra-thin FeAs is of interest both as the active component in the newly identified pnictide superconductors, and in spintronic applications at the interface between ferromagnetic Fe and semiconducting GaAs. Here we use first-principles…

The results of magnetic susceptibility, electrical resistivity ($\rho$), heat-capacity (C) and thermopower (S) measurements on CeCuAs2, forming in ZrCuSi2-type tetragonal structure, are reported. Our investigations reveal that Ce is…

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 first extensive measurements of the temperature dependence of phonon density of states of BaFe2As2, the parent compound of the newly discovered FeAs-based superconductors, using inelastic neutron scattering. The experiments…

The iron-based LaFeAsO$_{1-x}$F$_x$ recently discovered by Hosono's group is a fresh theoretical challenge as a new class of high-temperature superconductors. Here we describe the electronic structure of the material and the mechanism of…

The structural and magnetic phase transitions of the ternary iron arsenides SrFe2As2 and EuFe2As2 were studied by temperature-dependent x-ray powder diffraction and 57-Fe Moessbauer spectroscopy. Both compounds crystallize in the tetragonal…

Polycrystalline samples of underdoped (Ba1-xKx)Fe2As2 (x<=0.4) were synthesized and studied by x-ray powder diffraction, magnetic susceptibility, specific heat and 57Fe-Moessbauer-spectroscopy. The structural phase transition from…

Interface enhanced superconductivity at two dimensional limit has become one of most intriguing research directions in condensed matter physics. Here, we report the superconducting properties of ultra-thin FeSe films with the thickness of…

Low temperature specific heat (SH) was measured on the FeAs-based superconducting single crystals Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ and high pressure synthesized polycrystalline samples SmFeAsO$_{0.9}$F$_{0.1}$. It is found that the sharp SH…

In this paper we report the synthesis of iron-based superconductors CaFe2-xRhxAs2 using one-step solid state reaction method, which crystallizes in the ThCr2Si2-type structure with a space group I4/mmm. The systematic evolution of the…

We have employed a new route to synthesize single phase F-doped LaOFeAs compound and confirmed the superconductivity above 20 K in this Fe-based system. We show that the new superconductor has a rather high upper critical field of about 54…

We performed magnetization and electrical resistivity measurements under high pressures of up to 19 GPa for FeTe0.92. The compound shows an anomaly in magnetization and resistivity at atmospheric pressure due to a structural distortion…

Materials with exceptional magnetism and superconductivity usually conceive emergent physical phenomena. Here, we investigate the physical properties of the (Eu,La)FeAs2 system with double magnetic sublattices. The parent EuFeAs2 shows…

We report muon-spin relaxation measurements on SrFeAsF, which is the parent compound of a newly discovered iron-arsenic-fluoride based series of superconducting materials. We find that this material has very similar magnetic properties to…

A reentrant behavior of temperature dependent magnetic ac-susceptibility (or excess susceptibility(ES)) at lower temperature is observed in a composite made of superconductor $La_{1.85}Sr_{0.15}CuO_4$ (LCu) and an insulating paramagnetic…