Quenched Fe moment in the collapsed tetragonal phase of Ca1−xPrxFe2As2

@article{Ma2013QuenchedFM,
  title={Quenched Fe moment in the collapsed tetragonal phase of Ca1−xPrxFe2As2},
  author={Long Ma and G. F. Ji and Jianhui Dai and S. R. Saha and Johnpierre Paglione and Weiqiang Yu},
  journal={Chinese Physics B},
  year={2013},
  volume={22},
  pages={057401}
}
We report 75As NMR studies on single crystals of rare-earth doped iron pnictide superconductor Ca1−xPrxFe2As2. In both cases of x = 0.075, 0.15, a large increase of νq upon cooling is consistent with the tetragonal-collapsed tetragonal structure transition. A sharp drop of the Knight shift is also seen just below the structure transition, which suggests the quenching of Fe local magnetism, and therefore offers important understanding of the collapsed tetragonal phase. At even low temperatures… 

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References

SHOWING 1-10 OF 55 REFERENCES
Pressure-induced volume-collapsed tetragonal phase of CaFe2As2 as seen via neutron scattering
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
Suppression of antiferromagnetic spin fluctuations in the collapsed phase of CaFe2As2
Inelastic neutron scattering measurements of CaFe2As2 under applied hydrostatic pressure show that the antiferromagnetic spin fluctuations observed in the ambient pressure, paramagnetic, tetragonal
Pressure induced superconductivity in CaFe2As2.
CaFe2As2 has been found to be exceptionally sensitive to the application of hydrostatic pressure and can be tuned to reveal all the salient features associated with FeAs superconductivity without
Superconducting and ferromagnetic phases induced by lattice distortions in stoichiometric SrFe2As2 single crystals.
Single crystals of SrFe2As2 grown using a self-flux solution method were characterized via x-ray, transport, and magnetization studies, revealing a superconducting phase below Tc=21 K characterized
Magnetic Ordering and Negative Thermal Expansion in PrFeAsO
We report the structure and magnetism of PrFeAsO, one of the parent phases of the Fe-As family of superconductors, as measured by neutron powder diffraction. In common with other REFeAsO materials, a
Unusual superconducting state at 49 K in electron-doped CaFe2As2 at ambient pressure
  • B. Lv, L. Deng, C. Chu
  • Physics
    Proceedings of the National Academy of Sciences
  • 2011
TLDR
The detection of unusual superconductivity up to 49 K in single crystalline CaFe2As2 via electron-doping by partial replacement of Ca by rare-earth suggests the possible existence of two phases: one starting at 49 K, which has a low critical field < 4 Oe, and the other at 21 K, with a much higher critical field > 5 T.
NMR investigation of superconductivity and Antiferromagnetism in CaFe2As2 under pressure.
TLDR
75As NMR measurements in CaFe2As2 and 75As spin-lattice relaxation experiments indicate that the 75As nuclei sample the superconductivity while in the magnetically ordered environment.
First-order magnetic transition in single-crystalline CaFe 2 As 2 detected by A75s nuclear magnetic resonance
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
Superconductivity at 41 K and its competition with spin-density-wave instability in layered CeO1-xFxFeAs.
TLDR
The study reveals that the Ce 4f electrons form local moments and are ordered antiferromagnetically below 4 K, which could coexist with superconductivity, which strongly challenges the classic BCS theory based on the electron-phonon interaction.
Anomalous compressibility effects and superconductivity of EuFe2As2 under high pressures.
TLDR
P-V data or the equation of state for EuFe( 2)As(2) both in the ambient tetragonal phase and in the high pressure collapsed tetragon phase up to 70 GPa is presented.
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