Related papers: Synthesis, anisotropy, and superconducting propert…
The temperature dependent resistivity of Ba$_{1-x}$K$_x$Fe$_2$As$_2$ (x = 0.23, 0.25, 0.28 and 0.4) single crystals and the angle dependent resistivity of superconducting Ba$_{0.6}$K$_{0.4}$Fe$_2$As$_2$ single crystals were measured in…
Anisotropic superconducting properties including the upper critical field Hc2, thermal activation energy U0, and critical current density Jc are systematically studied in a large Ca1-xLaxFeAs2 single crystal (x ~ 0.18). The obtained Hc2…
We report the crystal growth and structural, magnetic, conductivity, and specific heat investigations of Rb(1-x)Fe(2-y)Se2 single crystals with varying stoichiometry prepared by self-flux and Bridgman methods. The system exhibits a strongly…
We report resistivity measurements performed on KFe$_2$As$_2$ single crystals down to $T$ = 0.3 K and in magnetic fields up to 17.5 T. The in-plane resistivity vs. $T$ curve has a convex shape down to $\sim$50 K and shows a $T^2$ dependence…
We successfully grew the high-quality single crystals of $A_{x}$Fe$_2$Se$_2$ ($A$ = K and Cs) by self-flux method. Sharp superconducting transition was observed for both types of crystals. The crystals show the onset superconducting…
LiFeAs is unique among the broad family of FeAs-based superconductors, because it is superconducting with a rather large $T_c\simeq 18$ K under ambient conditions although it is a stoichiometric compound. We studied the electrical transport…
Single crystals of BaFe$_2$As$_2$ and (Ba$_{0.55}$K$_{0.45}$)Fe$_2$As$_2$ have been grown out of excess Sn with 1% or less incorporation of solvent. The crystals are exceptionally micaceous, are easily exfoliated and can have dimensions as…
We report on the upper critical field B_c2 of a superconducting LiFeAs single crystal with T_c~16 K, determined from magnetic torque measurements in dc-magnetic fields up to 35 T and at temperatures down to 0.3 K. B_c2 at 0.3 K is obtained…
The newly discovered iron-based superconductors have stimulated enormous interests in the field of superconductivity. Since the new superconductor is a layered system, the anisotropy is a parameter with the first priority to know. Meanwhile…
F-substituted LaOBiSe2 single crystals were grown using CsCl flux. The obtained single crystals showed a plate-like shape with a size of about 1.0 mm square. The c-axis lattice constant of the grown crystals was determined to be 14.114(3)…
A review of our investigations on single crystals of LnFeAsO1-xFx (Ln=La, Pr, Nd, Sm, Gd) and Ba1-xRbxFe2As2 is presented. A high pressure technique has been applied for the growth of LnFeAsO1-xFx crystals, while Ba1-xRbxFe2As2 crystals…
Single crystals of K0.58Fe1.56Se2 were successfully synthesized by a new single step process with the onset superconducting transition temperatures 31.9 K. The x-ray diffraction patterns suggest that they have high crystalline quality and…
The transport and superconducting properties of Ba_{1-x}K_xFe_2As_2 single crystals with T_c = 31 K were studied. Both in-plane and out-of plane resistivity was measured by modified Montgomery method. The in-plane resistivity for all…
Millimeter sized single crystals of KCa_2Fe_4As_4F_2 were grown using a self-flux method. The chemical compositions and crystal structure were characterized carefully. Superconductivity with the critical transition T_c = 33.5 K was…
Single crystals of the compound LaFePO were prepared using a flux growth technique at high temperatures. Electrical resistivity measurements reveal metallic behavior and a resistive transition to the superconducting state at a critical…
High-pressure electrical resistivity measurements up to 3.0GPa have been performed on EuFe2As2 single crystals with residual resistivity ratios RRR=7 and 15. At ambient pressure, a magnetic / structural transition related to FeAs-layers is…
Large high-quality single crystals of hole-doped iron-based superconductor (Ba$_{1-x}$K$_x$)Fe$_2$As$_2$ were grown over a broad composition range $0.22 \leq x \leq 1$ by inverted temperature gradient method. We found that high soaking…
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…
We report results of microwave surface impedance measurements of LiFeAs single crystals. The in-plane penetration depth depends on temperature exponentially at low temperatures, which strongly suggests that this material has the nodeless…
The temperature dependence of the upper critical magnetic field (Hc2) in a BaFe1.84Co0.16As2 single crystal was determined via resistivity, for the inter-plane (H^ab) and in-plane (H//ab) directions in pulsed and static magnetic fields of…