Combined effects of Sr substitution and pressure on the ground states in CaFe${}_2$As${}_2$

Abstract

We present a detailed study of the combined effects of Sr substitution and hydrostatic pressure on the ground-state properties of CaFe${}_2$As${}_2$. Measurements of the electrical resistance and magnetic susceptibility, both at ambient and finite pressure $P$ $\le$ 2GPa, were performed on Ca${}_{1-x}$Sr${}_x$Fe${}_2$As${}_2$ single crystals grown out of Sn flux. We find that upon Sr substitution the ranges of stability of both the structural-magnetic transition and the transition into the non-magnetic collapsed tetragonal phase are shifted to higher pressure levels with the latter moving at a higher rate. This suggests the possibility of separating the two phase lines, which intersect already at elevated temperatures for $x$ = 0 and low Sr concentration levels. For $x$ = 0.177 we find strong evidence that both phases remain separated down to lowest temperature and that a zero-resistance state emerges in this intermediate pressure window. This observation indicates that Sr-substitution combined with hydrostatic pressure provides another route for stabilizing superconductivity in CaFe${}_2$As${}_2$. Our results are consistent with the notion that (i) preserving the fluctuations associated with the structural-magnetic transition to low temperatures is vital for superconductivity to form in this material and that (ii) the non-magnetic collapsed tetragonal phase is detrimental for superconductivity.

arXiv comment11 pages, 10 figures

References in corpus (25)

• Pressure induced superconductivity in CaFe${}_2$As${}_2$
• Pressure-induced volume-collapsed tetragonal phase of CaFe2As2 as seen via neutron scattering
• Lattice and magnetic instabilities in CaFe2As2: A single crystal neutron diffraction study
• First order structural phase transition in CaFe${}_2$As${}_2$
• Complete pressure dependent phase diagrams for SrFe2As2 and BaFe2As2
• The Absence of Superconductivity in Single Phase CaFe2As2 under Hydrostatic Pressure
• Structural transition and anisotropic properties of single crystalline SrFe2As2
• Lattice collapse and quenching of magnetism in CaFe2As2 under pressure: A single crystal neutron and x-ray diffraction investigation
• Structural collapse and superconductivity in rare earth-doped CaFe2As2
• Pressure-induced superconductivity in single crystal CaFe2As2
• Structural, magnetic and superconducting phase transitions in CaFe2As2 under ambient and applied pressure
• The giant plasticity of a quantum crystal
• Stabilization of an ambient pressure, collapsed tetragonal phase in CaFe2As2 and tuning of the orthorhombic / antiferromagnetic transition temperature by over 70 K by control of nano-precipitates
• Presure-Induced Superconducting State of Antiferromagnetic CaFe${}_2$As${}_2$
• High pressure study of BaFe2As2 - role of hydrostaticity and uniaxial stress
• Evolution of bulk superconductivity in SrFe2As2 with Ni substitution
• Control of magnetic, non-magnetic and superconducting states in annealed Ca(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• Symmetry preserving lattice collapse in tetragonal SrFe_(2-x)Ru_xAs_2 (x = 0, 0.2) -- a combined experimental and theoretical study
• Hydrostatic-pressure tuning of magnetic, nonmagnetic and superconducting states in annealed Ca(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$
• Evidence from neutron diffraction for superconductivity in the stabilized tetragonal phase of CaFe2As2 under uniaxial pressure
• Upper critical field of KFe2As2 under pressure: A test for the change in the superconducting gap structure
• Resistivity and magnetoresistance of FeSe single crystals under Helium-gas pressure
• The suppression of magnetism and the development of superconductivity within the collapsed tetragonal phase of Ca0.67Sr0.33Fe2As2 at high pressure
• Tuning magnetism in FeAs-based materials via tetrahedral structure
• Uniform chemical pressure effect in solid solutions Ba(1-x)Sr(x)Fe2As2 and Sr(1-x)Ca(x)Fe2As2

Cited by in corpus (3)

• Hydrostatic and uniaxial pressure tuning of iron-based superconductors: Insights into superconductivity, magnetism, nematicity and collapsed tetragonal transitions
• Wavefunctions, electronic localization and bonding properties for correlated materials beyond the Kohn-Sham formalism
• The collapsed tetragonal phase as a strongly covalent and fully nonmagnetic state: persistent magnetism with interlayer As-As bond formation in Rh-doped Ca${}_{0.8}$Sr${}_{0.2}$Fe${}_2$As${}_2$