Publications by Janusz Andrzej Karpinski

Single crystals of superconducting SmFeAsOHx: Structure and properties

László Forró, Andrea Pisoni, Alla Arakcheeva, Richard Gaal, Janusz Andrzej Karpinski, Sergiy Katrych, Ping Huang, Péter Krisztián Matus

We report the synthesis, structure, and superconducting properties of single crystals of SmFeAsOHx. The crystals were grown at high pressure and high temperature using a cubic anvil technique. H-1-NMR studies confirm the presence of H atoms in the samples. ...

Amer Physical Soc2016

Upper critical field, pressure-dependent superconductivity and electronic anisotropy of Sm4Fe2As2Te1-xO4-yFy

László Forró, Andrea Pisoni, Richard Gaal, Bálint Náfrádi, Janusz Andrzej Karpinski, Sergiy Katrych, Péter Szirmai

We present a detailed study of the electrical transport properties of a recently discovered iron-based superconductor: Sm4Fe2As2Te0.72O2.8F1.2. We followed the temperature dependence of the upper critical field by resistivity measurement of single crystals ...

Iop Publishing Ltd2016

Magnetotransport studies of superconducting Pr4Fe2As2Te1-xO4

László Forró, Andrea Pisoni, Richard Gaal, Bálint Náfrádi, Janusz Andrzej Karpinski, Sergiy Katrych, Péter Szirmai

We report a study of the electrical transport properties of single crystals of Pr(4)Fe(2)As(2)Te(1-)xO(4), a recently discovered iron-based superconductor. Resistivity, Hall effect, and magnetoresistance are measured in a broad temperature range revealing ...

Amer Physical Soc2016

Local lattice distortions vs. structural phase transition in NdFeAsO1-xFx

Sergiy Katrych, Janusz Andrzej Karpinski

The lattice properties at low temperatures of two samples of NdFeAsO1-xFx (x = 0.05 and 0.25) have been examined in order to investigate possible structural phase transition that may occur in the optimally doped superconducting sample with respect to the n ...

Elsevier2016

Inhomogeneity of charge-density-wave order and quenched disorder in a high-T-c superconductor

Janusz Andrzej Karpinski, Davide Innocenti

It has recently been established that the high-transition-temperature (high-T-c) superconducting state coexists with short-range charge-density-wave order(1-11) and quenched disorder(12,13) arising from dopants and strain(14-17). This complex, multiscale p ...

Nature Publishing Group2015

Mossbauer studies of the peculiar magnetism in parent compounds of the iron-based superconductors

Janusz Andrzej Karpinski

A review of the magnetism in the parent compounds of the iron-based superconductors is given based on the transmission Mossbauer spectroscopy of Fe-57 and Eu-151. It was found that the 3d magnetism is of the itinerant character with varying admixture of th ...

Taylor & Francis Ltd2015

Measurement of the penetration depth and coherence length of MgB2 in all directions using transmission electron microscopy

Janusz Andrzej Karpinski

We demonstrate that images of flux vortices in a superconductor taken with a transmission electron microscope can be used to measure the penetration depth and coherence length in all directions at the same temperature and magnetic field. This is particular ...

Amer Physical Soc2015

Slow magnetic fluctuations and superconductivity in fluorine-doped NdFeAsO

Sergiy Katrych, Janusz Andrzej Karpinski

Among the widely studied superconducting iron-pnictide compounds belonging to the Ln1111 family (with Ln a lanthanide), a systematic investigation of the crossover region between the superconducting and the antifer-romagnetic phase for the Ln = Nd case has ...

Amer Physical Soc2015

Critical current anisotropy in Nd-1111 single crystals and the influence of neutron irradiation

Sergiy Katrych, Janusz Andrzej Karpinski

We report on angle-resolved magnetization measurements on NdFeAsO0.65F0.35 ( Nd-1111) single crystals. The field dependence of the critical current density, Jc, is non-monotonic in these crystals at all orientations and temperatures due to the fishtail eff ...

Iop Publishing Ltd2014

Electric field gradient wave (EFGW) in iron-based superconductor Ba0.6K0.4Fe2As2 studied by Mossbauer spectroscopy

Janusz Andrzej Karpinski

The optimally doped '122' iron-based superconductor Ba0.6K0.4Fe2As2 has been studied by Fe-57 Mossbauer spectroscopy versus temperature ranging from 4.2 K till 300 K with particular attention paid to the superconducting transition around 38 K. The spectra ...

Elsevier Science Sa2014