Related papers: MAGNETIC ANOMALY IN SUPERCONDUCTING FeSe
We successfully synthesized two new compounds Rb$_x$Fe$_{2-y}$S$_2$ and Cs$_x$Fe$_{2-y}$S$_2$ which were isostructural with K$_x$Fe$_{2-y}$Se$_2$ superconductor. We systematically investigated the resistivity, magnetism and thermoelectric…
The bulk polycrystalline sample FeSe1/2Te1/2 is synthesized by solid state reaction route in an evacuated sealed quartz tube at 750 oC. The presence of superconductivity is confirmed through magnetization/thermoelectric/resistivity studies.…
Superconductivity with transition temperature Tc above 40 K was observed in protonated FeSe (Hy-FeSe) previously with the ionic liquid of EMIM-BF4 used in the electrochemical process. However, the real superconducting phase is not clear…
We present the complex harmonic magnetic susceptibilities of the FeSeTe polycrystalline superconducting sample. The ac magnetic susceptibility is measured as a function of various external perturbations such as temperature, the AC magnetic…
The heat-capacity and magnetization measurements under high pressure have been carried out in a ferromagnetic superconductor UGe$_2$. Both measurements were done using a same pressure cell in order to obtain both data for one pressure.…
Potassium intercalated FeSe has been reported as a superconductor with superconducting transition temperatures ($T_{\rm c}$'s) of 30-48 K. However, there is no clear answer to identify the relationship between the surface morphology,…
The intrinsic pinning properties of FeSe0.5Te0.5, which is the superconductor with Tc of about 14 K, were studied by the analysis of magnetization curves by the extended critical state model. In the magnetization measurements by SQUID…
Both DC and AC magnetization measurements were performed on the NdFeAsO0.88F0.12 superconductor to investigate the influence of magnetism on the superconducting properties of this system. The crossover of the ZFC and FC magnetic…
High-temperature superconductivity occurs near antiferromagnetic instabilities and nematic state. Debate remains on the origin of nematic order in FeSe and its relation with superconductivity. Here, we use transport, neutron scatter- ing…
The magnetization anisotropy of a layered superconductor FeTe0.65Se0.35 sample is experimentally studied in a magnetic field directed either along the layers of the plane, or perpendicular to them. The value of the vortex pinning potential…
We report on structural, susceptibility, conductivity, and heat-capacity studies of FeSe0.5Te0.5 single crystals with 2% substitution of Mn for Fe. Mn-doped samples show a higher onset temperature, a narrower width of the superconducting…
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…
The FeSe superconductor and its related systems have attracted much attention in the iron-based superconductors owing to their simple crystal structure and peculiar electronic and physical properties. The bulk FeSe superconductor has a…
The recent discovery and subsequent developments of FeAs-based superconductors have presented novel challenges and opportunities in the quest for superconducting mechanisms in correlated-electron systems. Central issues of ongoing studies…
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…
We investigated the pressure effects on the FeSe superconductor and the related compounds. Pressure dependence of superconducting transition temperature (Tc) for FeSe0.8S0.2 exhibits a dome-shaped behavior below 0.76 GPa. On the other hand,…
Magnetotransport properties of the high-quality FeSe crystal, measured in a wide temperature range and in magnetic fields up to 50 T, show the symmetry of the main holelike and electronlike bands in this compound. In addition to the main…
We present measurements of the temperature and field dependencies of the magnetization M(T,H) of Nd(O0.89F0.11)FeAs at fields up to 33T, which show that superconductivity with the critical temperature Tc ~ 51K cannot coexist with…
In this article we review our studies of the K0.80Fe1.76Se2 superconductor, with an attempt to elucidate the crystal growth details and basic physical properties over a wide range of temperatures and applied magnetic field, including…
In this article, we examine the superconducting properties of low- and high-$T_c$ magnetic superconductors in magnetic fields close to the first penetration field. Attention is paid to the properties that relate to the interactions between…