相关论文: Microscopic co-existence of superconductivity and …

Unconventional superconductivity arises at the border between the strong coupling regime with local magnetic moments and the weak coupling regime with itinerant electrons, and stems from the physics of criticality that dissects the two.…

The electronic and magnetic properties of a new diluted magnetic semiconductor (DMS) Ba$_{1-x}$K$_{x}$(Zn$_{1-y}$Mn$_{y}$)$_{2}$As$_{2}$, which is isostructural to so-called 122-type Fe-based superconductors, are investigated by x-ray…

The thermal conductivity kappa of the iron-arsenide superconductor Ba1-xKxFe2As2 was measured for heat currents parallel and perpendicular to the tetragonal c axis at temperatures down to 50 mK and in magnetic fields up to 15 T.…

We report extensive muon spin rotation measurements on the lightly doped Y1-xCaxBa2Cu3O6+y compound, which allows us to disentangle the effect of disorder, controlled by random Ca2+ substitution, from that of mere doping. A 3D phase diagram…

Imaging local magnetic field distribution in a single crystal of superconductor CaFe1.94Co0.06As2 shows the presence of anomalous remnant magnetization within Meissner like regions of the sample. Close to the superconducting transition…

In this paper we report the superconductivity above 40 K in the electron doping single crystal Ca1-xRexFe2As2 (Re = La, Ce, Pr). The x-ray diffraction patterns indicate high crystalline quality and c-axis orientation. the resistivity…

An elementary model of La2-xSrxCuO4 explaining the features of its superconducting phase diagram and the characteristics of spin textures without any assumption of stripe formation is proposed. The foundations of this model are the…

Single phase, sol-gel prepared Cu1-xFexO (0<x<0.125) are characterized in terms of structural, electronic and magnetic properties. Using dielectric and magnetic studies we investigate the coupling of electron and spin. The electrical…

High-transition-temperature (high-Tc) superconductivity develops near antiferromagnetic phases, and it is possible that magnetic excitations contribute to the superconducting pairing mechanism. To assess the role of antiferromagnetism, it…

75As NMR and susceptiblity were measured in a Ba(Fe1-xCox)2As2 single crystal for x=6% for various field H values and orientations. The sharpness of the superconducting and magnetic transitions demonstrates a homogeneity of the Co doping x…

High-resolution and high-flux neutron as well as X-ray powder-diffraction experiments were performed on the oxypnictide series LaO(1-x)FxFeAs with 0<x<0.15 in order to study the crystal and magnetic structure. The magnetic symmetry of the…

We investigated the optical spectrum of Ba(Fe1-xCox)2As2 single crystals with various doping levels. It is found that the low-energy optical conductivity spectrum of this system can be decomposed into two components: a sharp Drude term and…

We report on specific heat measurements in Ba$_{1-x}$K$_x$Fe$_{2}$As$_{2}$ ($x\le 0.6$). For the underdoped sample with $x=0.2$ both the spin-density-wave transition at $T = 100$ K and the superconducting transition at 23 K can be…

Measurements of the magnetic penetration depth (lambda) in the Fe-based superconductor Ba_(1-x)Rb_xFe_2As_2 (x=0.3, 0.35, 0.4) were carried out using the muon-spin rotation muSR technique. The temperature dependence of lambda is well…

An extensive calorimetric study of the normal- and superconducting-state properties of Ba(Fe1-xCox)2As2 is presented for 0 < x < 0.2. The normal-state Sommerfeld coefficient increases (decreases) with Co doping for x < 0.06 (x > 0.06),…

Theoretically, the relative change of the Heisenberg-type nearest-neighbor coupling $J_1$ and next-nearest-neighbor coupling $J_2$ in the face-centered-cubic lattice can give rise to three main antiferromagnetic orderings of type-I,…

Superconductivity is achieved in Nd1-xCexOBiS2 via electron doping using mixed-valence Ce ions. Single crystals with x = 0.2, 0.3, 0.4, and 0.5 are generated using a CsCl flux method. Plate-like single crystals with dimensions of 0.8 0.8…

The superconductivity in high temperature superconductors ordinarily arises when doped with hetero-valent ions that introduce charge carriers. However, in ferropnictides, "iso-valent" doping, which is generally believed not to introduce…

Here, we present a combination of magnetization and magnetic torque experiments to investigate the magnetic orders in undoped EuFe2As2 and Co doped EuFe1.8Co0.2As2 single crystals. Although at low temperatures typical results for an…

Recent experiments demonstrated that isovalent doping system gives the similar phase diagram as the heterovalent doped cases. For example, with the phosphorous (P)-doping, the magnetic order in BaFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ compound…