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

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57Fe-M\"ossbauer studies of superconducting Rb0.8Fe1.6Se2.0 with TC = 32.4 K were performed on single-crystalline and polycrystalline samples in the temperature range 4.2 K to 295 K. They reveal the presence of 88% magnetic and 12%…

Superconductivity · Physics 2011-08-16 V. Ksenofontov , G. Wortmann , S. Medvedev , V. Tsurkan , J. Deisenhofer , A. Loidl , C. Felser

Recent high-pressure studies found that superconductivity can be achieved under very low pressure in the parent iron arsenide compound CaFe2As2, although details of the sharpness and temperature of transitions vary between liquid medium and…

Superconductivity · Physics 2009-11-13 W. Yu , A. A. Aczel , T. J. Williams , S. L. Bud'ko , N. Ni , P. C. Canfield , G. M. Luke

We report $^{75}$As NMR measurements in CaFe$_2$As$_2$, made under applied pressures up to 0.83 GPa produced by a standard clamp pressure cell. Our data reveal phase segregation of paramagnetic (PM) and antiferromagnetic (AFM) phases over a…

Superconductivity · Physics 2009-06-04 S. -H. Baek , H. Lee , S. E. Brown , N. J. Curro , E. D. Bauer , F. Ronning , T. park , J. D. Thompson

The measurements of the magnetic susceptibility, magnetization, electrical resistivity and magnetoresistance have been performed for the Fe intercalated compound Fe0.5TiS2. According to X-ray diffraction measurements the Fe0.5TiS2 compound…

On experimental side, BaFe$_2$As$_2$ without doping has been made superconducting by applying appropriate pressure (2-6 GPa). Here, we use a full-potential linearized augmented plane wave method within the density-functional theory to…

Superconductivity · Physics 2009-04-08 Wenhui Xie , Mingli Bao , Zhenjie Zhao , Bang-Gui Liu

$^{57}$Fe M\"ossbauer spectra at different temperatures between $\sim 5$ K and $\sim 300$ K were measured on an oriented mosaic of single crystals of CaKFe$_4$As$_4$ . The data indicate that CaKFe$_4$As$_4$ is a well formed compound with…

Superconductivity · Physics 2017-11-01 Sergey L. Bud'ko , Tai Kong , William R. Meier , Xiaoming Ma , Paul C. Canfield

We present a detailed study of magnetization, resistivity, heat capacity, and X-ray and neutron powder diffraction measurements performed on single crystals of non-stoichiometric CeAuBi$_2$, Au deficiency 18$\%$, a strongly correlated…

We present a systematic 57Fe-Moessbauer study on highly diluted Fe centers in Li2(Li1-xFex)N single-crystals as a function of temperature and magnetic field applied transverse and longitudinal with respect to the single-ion anisotropy axis.…

Strongly Correlated Electrons · Physics 2020-08-26 S. A. Braeuninger , A. Jesche , S. Kamusella , F. Seewald , M. Fix , R. Sarkar , A. A. Zvyagin , H. -H. Klauss

Co-doped BaFe2As2 has been previously shown to have an unusually significant improvement of Tc (up to 2 K, or almost 10%) with annealing 1-2 weeks at 700 or 800 C, where such annealing conditions are insufficient to allow significant atomic…

Superconductivity · Physics 2015-06-19 J. S. Kim , G. N. Tam , G. R. Stewart

Recent investigations of the superconducting iron-arsenide families have highlighted the role of pressure, be it chemical or mechanical, in fostering superconductivity. Here we report that CaFe2As2 undergoes a pressure-induced transition to…

The structural properties of the CaFe2As2 have been investigated by x-ray and neutron powder diffraction techniques as a function of temperature. Unambiguous experimental evidence is shown for coexistence of tetragonal and orthorhombic…

Superconductivity · Physics 2013-11-27 S. K. Mishra , R. Mittal , P. S. R. Krishna , P. U. Sastry , S. L. Chaplot , P. D. Babu , S. Matsuishi , H. Hosono

57Fe Mossbauer spectroscopy measurements were performed on a powdered CuFe2Ge2 sample that orders antiferromagnetically at ~ 175 K. Whereas a paramagnetic doublet was observed above the Neel temperature, a superposition of paramagnetic…

Materials Science · Physics 2018-03-14 Sergey L. Bud'ko , Na Hyun Jo , Savannah S. Downing , Paul C. Canfield

We report anisotropic dc magnetic susceptibility $\chi(T)$, electrical resistivity $\rho(T)$, and heat capacity $C(T)$ measurements on the single crystals of CaFe$_{2-x}$Co$_x$As$_2$ for $x$ = 0 and 0.06. Large sized single crystals were…

Superconductivity · Physics 2009-11-13 Neeraj Kumar , R. Nagalakshmi , R. Kulkarni , P. L. Paulose , A. K. Nigam , S. K. Dhar , A. Thamizhavel

Magnetic measurements and 57Fe Mossbauer spectroscopy studies were performed on oxygen- deficient high temperature superconductor SmFeAsO0.85 with TC=52.4 K. The upper-critical behavior (HC2) values were extracted from the real part of ac…

We investigate magnetic ordering in metallic Ba[Fe(1-x)Mn(x)](2)As(2) and discuss the unusual magnetic phase, which was recently discovered for Mn concentrations x > 10%. We argue that it can be understood as a Griffiths-type phase that…

The static and the dynamic spin correlations in the low temperature collapsed tetragonal and the high temperature tetragonal phase in CaFe2As2 have been investigated by 75As nuclear magnetic resonance (NMR) and nuclear quadrupole resonance…

Superconductivity · Physics 2015-06-18 Y. Furukawa , B. Roy , S. Ran , S. L. Bud'ko , P. C. Canfield

We present the results of electrical resistivity, ac specific heat, magnetic susceptibility, X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) of the ternary iron arsenide EuFe2As2 single crystal under…

Magnetism in the orthorhombic metal CaFe$_4$As$_3$ was examined through neutron diffraction for powder and single crystalline samples. Incommensurate (${\bm q}_{\rm m}\approx (0.37-0.39)\times{\bm b}^{\ast}$) and predominantly…

We report systematic investigation of high pressure crystal structures and structural phase transition upto 46 GPa in CaFeAsF and 40 GPa in SrFeAsF at 40 K using powder synchrotron x-ray diffraction experiments and Rietveld analysis of the…

We report $^{75}$As Nuclear Magnetic Resonance data in a single crystal of CaFe$_2$As$_2$. The Knight shift, electric field gradient, and spin-lattice relaxation rate are strongly temperature dependent in the paramagnetic state, and change…

Strongly Correlated Electrons · Physics 2009-02-11 S. -H. Baek , N. J. Curro , T. Klimczuk , E. D. Bauer , F. Ronning , J. D. Thompson