Pressure-induced superconductivity in Eu${}_{0.5}$Ca${}_{0.5}$Fe${}_2$As${}_2$ : FeAs-based superconductivity hidden by antiferromagnetism of Eu sublattice

Abstract

To clarify superconductivity in EuFe2As2 hidden by antiferromagnetism of Eu2+, we investigated a Ca-substituted sample, Eu0.5Ca0.5Fe2As2, under high pressure. For ambient pressure, the sample exhibits a spin-density-wave (SDW) transition at TSDW = 191 K and antiferromagnetic order at TN = 4 K, but no evidence of superconductivity down to 2 K. The Ca-substitution certainly weakens the antiferromagnetism. With increasing pressure, TSDW shifts to lower temperature and becomes more unclear. Above 1.27 GPa, pressure-induced superconductivity with zero resistivity is observed at around Tc = 20 K. At 2.14 GPa, Tc reaches a maximum value of 24 K and the superconducting transition becomes the sharpest. These features of emergence of the superconductivity are qualitatively similar to those observed in AFe2As2 (A = Ba, Ca).

4 pages, 4 figures

References in corpus (20)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• Superconductivity at 43 K in Samarium-arsenide Oxides $SmFeAs{O}_{1-x}{F}_x$
• Superconductivity at 22 K in Co-doped BaFe2As2 Crystals
• Spin density wave anomaly at 140 K in the ternary iron arsenide BaFe2As2
• Superconductivity up to 37 K in (A1-xSrx)Fe2As2 with A=K and Cs
• Pressure induced superconductivity in CaFe${}_2$As${}_2$
• First order structural phase transition in CaFe${}_2$As${}_2$
• Superconductivity induced by phosphorus doping and its coexistence with ferromagnetism in EuFe${}_2$(As${}_{0.7}$P${}_{0.3}$)${}_2$
• Crystallographic Phase Transition and High-Tc Superconductivity in LaFeAsO:F
• Superconductivity in SrFe_(2-x)Co_xAs_2: Internal Doping of the Iron Arsenide Layers
• High-Temperature Superconductivity in Eu0.5K0.5Fe2As2
• Antiferromagnetic transition in EuFe${}_2$As${}_2$: A possible parent compound for superconductors
• The Absence of Superconductivity in Single Phase CaFe2As2 under Hydrostatic Pressure
• Possible re-entrant superconductivity in EuFe2As2 under pressure
• Magnetic structure of EuFe2As2 determined by single crystal neutron diffraction
• EuFe${}_2$As${}_2$ under high pressure: an antiferromagnetic bulk superconductor
• Abrupt Emergence of Pressure-Induced Superconductivity of 34 K in SrFe2As2: A Resistivity Study under Pressure
• Presure-Induced Superconducting State of Antiferromagnetic CaFe${}_2$As${}_2$
• Effect of Uniaxial Stress for Pressure-Induced Superconductor SrFe_2As_2

Cited by in corpus (4)

• Electron spin resonance in Eu based Fe pnictides
• Magnetic phase diagram of Ca-substituted EuFe${}_2$As${}_2$
• High-Pressure Electrical Resistivity Measurements of EuFe2As2 Single Crystals
• Re-entrance of resistivity due to the interplay of superconductivity and magnetism in $\ce{Eu_{0.73}Ca_{0.27}(Fe_{0.87}Co_{0.13})2As2}$