Systematic Study of Vortex Pinning and a Liquid–Glass Phase Transition in BaFe<Subscript>2–<Emphasis Type="Italic">x</Emphasis></Subscript>Ni<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>As<Subscript>2</Subscript> Single Crystals

The vortex pinning and liquid-glass transition have been studied in BaFe_2–xNi _x As₂ single crystals with different doping levels (x = 0.065, 0.093, 0.1, 0.14, 0.18). We found that Ni-doped Ba-122 has rather narrow vortex-liquid state region. Our results show that the temperature dependence of the resistivity as well as I?V characteristics of Ni-doped Ba-122 is consistent with 3D vortex-glass model. It was found that -pinning gives the main contribution to overall pinning in 122 Ni-doped system. The vortex phase diagrams for different doping levels were built based on the obtained data of temperature of the vortex-glass transition T_g and the upper critical magnetic field H_c2.     

Multiple Andreev Reflection Spectroscopy of Optimally Doped Ba(Fe,Ni)2As2 Superconducting Pnictides

JETP Letters - The current-voltage characteristics and dynamic conductance spectra of the SnS junction in Ba(Fe, Ni)2As2 superconducting pnictide of almost optimal composition have been obtained. A...     

New Ternary Bismuthides NaZnBi and NaCdBi: Synthesis and Crystal Structures

Russian Journal of Coordination Chemistry - Single crystals of new ternary bismuthides NaZnBi (I) and NaCdBi (II) are obtained by the self-flux technique. Its crystal structures are studied by...     

Electronic Structure of InCo2As2 and KInCo4As4: LDA + DMFT

JETP Letters - A comparative analysis of the electronic structure obtained in the DFT/LDA and LDA + DMFT approaches of the possible isostructural analogues of iron superconductors InCo2As2 and...     

Determination of the Superconducting Order Parameter of BaFe1.92Ni0.08As2 Weakly Underdoped Pnictides by Two Complementary Techniques

JETP Letters - The structure of the superconducting order parameter of weakly underdoped BaFe1.92Ni0.08As2 pnictides with the critical temperature Tc ≈ 18.2 K has been determined. Two...     

Upper Critical Field of a Two-Band SrFe2 − xNixAs2 Superconductor

JETP Letters - The upper critical field of an iron-based SrFe2 − xNixAs2 superconductor single crystal is measured for the first time in longitudinal and transverse magnetic fields up to 16 T...     

ARPES measurements of SnAs electronic band structure

A change in the time dependence of the second moment of the distribution of intensities of coherences with various orders in the spectrum of multiple-quantum NMR in a solid at the inclusion of an inhomogeneous magnetic field in the effective interaction is studied. Both the secular dipole–dipole and nonspecular twoquantum interactions are considered as nucleus–nucleus interactions, which correspond to traditional experimental realizations. It is shown that, with an increase in the magnitude of the inhomogeneous field, an exponential increase in the second moment of multiple-quantum NMR with time changes to a power-law increase. The results obtained in this work indicate that this second moment, which determines the average number of dynamically correlated spins, can be used as a convenient characteristic for studying a transition to a many-body localized state.     

Andreev Spectroscopy of EuCsFe4As4 Stoichiometric Superconducting Pnictide

JETP Letters - EuCsFe4As4 pnictide (1144 family) single crystals with a critical temperature of Tc ≈ 36.8 K and optimal superconducting properties in the stoichiometric composition are grown....