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Related papers: Mechanically-induced disorder in CaFe2As2: a 57Fe …

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TThe parent compounds of iron-arsenide superconductors, $A$Fe$_{2}$As$_{2}$ ($A$=Ca, Sr, Ba), undergo a tetragonal to orthorhombic structural transition at a temperature $T_{\mathrm{TO}}$ in the range 135 to 205K depending on the alkaline…

Strongly Correlated Electrons · Physics 2015-05-18 M. A. Tanatar , E. C. Blomberg , A. Kreyssig , M. G. Kim , N. Ni , A. Thaler , S. L. Bud'ko , P. C. Canfield , A. I. Goldman , I. I. Mazin , R. Prozorov

57Fe Moessbauer spectroscopy was applied to investigate the superconductor parent compound Fe(1+x)Te for x=0.06, 0.10, 0.14, 0.18 within the temperature range 4.2 K - 300 K. A spin density wave (SDW) within the iron atoms occupying regular…

Superconductivity · Physics 2012-09-04 A. Blachowski , K. Ruebenbauer , P. Zajdel , E. E. Rodriguez , M. A. Green

We present results from a detailed experimental investigation of LaFeAsO, the parent material in the series of "FeAs" based oxypnictide superconductors. Upon cooling this material undergoes a tetragonal-orthorhombic crystallographic phase…

The anisotropy of the Fe-based superconductors is much smaller than that of the cuprates and the theoretical calculations. A credible understanding for this experimental fact is still lacking up to now. Here we experimentally study the…

Superconductivity · Physics 2017-06-28 Yonghui Ma , Qiucheng Ji , Kangkang Hu , Bo Gao , Wei Li , Gang Mu , Xiaoming Xie

75As-zero-field nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements are performed on CaFe2As2 under pressure. At P = 4.7 and 10.8 kbar, the temperature dependences of nuclear-spin-lattice relaxation rate…

Superconductivity · Physics 2015-05-18 S. Kawasaki , T. Tabuchi , X. F. Wang , X. H. Chen , Guo-qing Zheng

57Fe and 151Eu Moessbauer spectra were obtained versus temperature for Eu0.57Ca0.43Fe2As2 compound with 3d and 4f magnetic order and Eu0.73Ca0.27(Fe0.87Co0.13)2As2 re-entrant superconductor, where the finite resistivity reappears while…

Superconductivity · Physics 2018-02-28 K. Komedera , A. Blachowski , K. Ruebenbauer , J. Zukrowski , S. M. Dubiel , L. M. Tran , M. Babij , Z. Bukowski

We report pressure-induced superconductivity in a single crystal of CaFe2As2. At atmospheric pressure, this material is antiferromagnetic below 170 K but under an applied pressure of 0.69 GPa becomes superconducting, with a transition…

Superconductivity · Physics 2008-07-18 Tuson Park , Eunsung Park , Hanoh Lee , T. Klimczuk , E D Bauer , F Ronning , J D Thompson

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…

Superconductivity · Physics 2012-12-27 Pabitra Mandal , Gorky Shaw , S. S. Banerjee , Neeraj Kumar , S . K. Dhar , A. Thamizhavel

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…

Superconductivity · Physics 2015-05-28 Z. Guguchia , S. Bosma , S. Weyeneth , A. Shengelaya , R. Puzniak , Z. Bukowski , J. Karpinski , H. Keller

Single crystals of Ba(Fe_(1-x)Mn_x)_2As_2, 0<x<0.148, have been grown and characterized by structural, magnetic, electrical transport and thermopower measurements. Although growths of single crystals of Ba(Fe_(1-x)Mn_x)_2As_2 for the full…

Superconductivity · Physics 2015-05-30 A. Thaler , H. Hodovanets , M. S. Torikachvili , S. Ran , A. Kracher , W. Straszheim , J. Q. Yan , E. Mun , P. C. Canfield

We investigated LaFeAsO single crystals by means of synchrotron M\"ossbauer spectroscopy under pressures up to 7.5 GPa and down to 13 K and provide a microscopic phase diagram. We found a continuous suppression of the magnetic hyperfine…

CaFe$_{2}$O$_{4}$ is an $S=5/2$ antiferromagnet exhibiting two magnetic orders which shows regions of coexistence at some temperatures. Using a Green's function formalism, we model neutron scattering data of the spin wave excitations in…

An ordered phase showing remarkable electronic anisotropy in proximity to the superconducting phase is now a hot issue in the field of high-transition-temperature superconductivity. As in the case of copper oxides, superconductivity in iron…

Strongly Correlated Electrons · Physics 2011-07-27 M. Nakajima , T. Liang , S. Ishida , Y. Tomioka , K. Kihou , C. H. Lee , A. Iyo , H. Eisaki , T. Kakeshita , T. Ito , S. Uchida

In the iron pnictides, the strong sensitivity of the iron magnetic moment to the arsenic position suggests a significant relationship between phonons and magnetism. We measured the phonon dispersion of several branches in the high…

The Eu-based compound, EuCu2As2, crystallizing in the ThCr2Si2-type tetragonal structure, has been synthesized and its magnetic behavior has been investigated by magnetization (M), heat-capacity (C) and electrical resistivity (rho)…

Strongly Correlated Electrons · Physics 2009-11-11 Kausik Sengupta , P. L. Paulose , E. V. Sampathkumaran , Th. Doert , J. P. F. Jemetio

The compound EuFe(2-x)Co(x)As2 was investigated by means of the 57Fe and 151Eu Moessbauer spectroscopy versus temperature (4.2 - 300 K) for x=0 (parent), x=0.34 - 0.39 (superconductor) and x=0.58 (overdoped). It was found that spin density…

Superconductivity · Physics 2011-11-08 A. Blachowski , K. Ruebenbauer , J. Zukrowski , Z. Bukowski , K. Rogacki , P. J. W. Moll , J. Karpinski

Aliovalent rare earth substitution into the alkaline earth site of CaFe2As2 single-crystals is used to fine-tune structural, magnetic and electronic properties of this iron-based superconducting system. Neutron and single crystal x-ray…

Superconductivity · Physics 2015-03-19 S. R. Saha , N. P. Butch , T. Drye , J. Magill , S. Ziemak , K. Kirshenbaum , P. Y. Zavalij , J. W. Lynn , J. Paglione

A new oxide, sodium iron antimonate, Na2FeSbO5, was synthesized and structurally characterized, and its static and dynamic magnetic properties were comprehensively studied both experimentally by dc and ac magnetic susceptibility,…

Density functional theory calculations within the generalized gradient approximation are employed to study the ground state of Co2FeAl. Various magnetic configurations are considered to find out its most stable phase. The ferromagnetic…

Strongly Correlated Electrons · Physics 2020-06-25 Aquil Ahmad , S. K. Srivastava , A. K. Das

By performing high-pressure single-crystal neutron diffraction measurements, the evolution of structure and magnetic ordering in EuFe2As2 under hydrostatic pressure were investigated. Both the tetragonal-toorthorhombic structural transition…

Superconductivity · Physics 2019-07-24 W. T. Jin , Y. Xiao , S. Nandi , S. Price , Y. Su , K. Schmalzl , W. Schmidt , T. Chatterji , A. Thamizhavel , Th. Brueckel