Multigap superconductivity in RbCa2Fe4As4F2 investigated using muSR measurements

Abstract

The superconducting properties of the recently discovered double Fe${}_2$As${}_2$ layered high-$T_c$ superconductor RbCa${}_2$Fe${}_4$As${}_4$F${}_2$ with $T_c\approx$ 30~K have been investigated using magnetization, heat capacity, transverse-field (TF) and zero-field (ZF) muon-spin rotation/relaxation ($\mu$SR) measurements. Our low field magnetization measurements and heat capacity (C${}_p$) reveal an onset of bulk superconductivity with $T_{\mathbf{c}}\sim$ 30.0(4) K. Furthermore, the heat capacity exhibits a jump at $T_{\mathbf{c}}$ of $\Delta$C${}_p$/$T_{\mathbf{c}}$=94.6 (mJ/mole-K${}^2$) and no clear effect of applied magnetic fields was observed on C${}_p$(T) up to 9 T between 2 K and 5 K. Our analysis of the TF-$\mu$SR results shows that the temperature dependence of the magnetic penetration depth is better described by a two-gap model, either isotropic $s$+$s$-wave or $s$+$d$-wave than a single gap isotropic $s$-wave or $d$-wave model for the superconducting gap. The presence of two superconducting gaps in RbCa${}_2$Fe${}_4$As${}_4$F${}_2$ suggests a multiband nature of the superconductivity, which is consistent with the multigap superconductivity observed in other Fe-based superconductors, including ACa${}_2$Fe${}_4$As${}_4$F${}_2$ (A=K and Cs). Furthermore, from our TF-$\mu$SR study we have estimated an in-plane penetration depth ${\lambda }_{\mathrm{ab}}$$(0)$ =231.5(3) nm, superconducting carrier density $n_s=7.45\times 10^{26}$m${}^{-3}$, and carrier's effective-mass $m^{\ast }$ = 2.45\textit{m}${}_e$. Our ZF $\mu$SR measurements do not reveal a clear sign of time reversal symmetry breaking at $T_{\mathbf{c}}$, but the temperature dependent relaxation between 150 K and 1.2 K might indicate the presence of spin-fluctuations. The results of our present study have been compared with those reported for other Fe pnictide superconductors.

arXiv comment10 pages, 7 figures. arXiv admin note: text overlap with arXiv:1706.03641

References in corpus (56)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• Superconductivity in Iron Compounds
• High-temperature superconductivity in iron-based materials
• Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2
• The superconductivity at 18 K in LiFeAs system
• Antiferromagnetic order and spin dynamics in iron-based superconductors
• Thorium-doping induced superconductivity up to 56 K in Gd1-xThxFeAsO
• Anion height dependence of Tc for the Fe-based superconductor
• Heavily electron-doped electronic structure and isotropic superconducting gap in AxFe2Se2 (A=K,Cs)
• Iron-Based Superconductors: current status of materials and pairing mechanism
• Magnetic Penetration Depth in Unconventional Superconductors
• Properties of the Ideal Ginzburg-Landau Vortex Lattice
• Unconventional Superconductivity
• Quantum criticality and nodal superconductivity in the FeAs-based superconductor KFe2As2
• Iron based high transition temperature superconductors
• Evidence for nodal superconductivity in LaFePO
• Evidence for superconducting gap nodes in the zone-centered hole bands of KFe2As2 from magnetic penetration-depth measurements
• Nodal superconducting gap structure in ferropnictide superconductor BaFe2(As0.7P0.3)2
• Observation of Time-Reversal Symmetry Breaking in the Non-Centrosymmetric Superconductor Re6Zr
• Universal heat conduction in the iron-arsenide superconductor KFe2As2 : Evidence of a d-wave state
• Superconductivity in Ca1-xLaxFeAs2: A Novel 112-Type Iron Pnictide with Arsenic Zigzag Bonds
• Specific heat jump at the superconducting transition temperature in Ba(Fe(1-x)Cox)2As2 and Ba(Fe(1-x)Nix)2As2 single crystals
• Anisotropic thermodynamic and transport properties of single crystalline CaKFe${}_4$As${}_4$
• Isotropic superconducting gaps with enhanced pairing on electron Fermi surfaces in FeTe0.55Se0.45
• Superconductivity in KCa${}_2$Fe${}_4$As${}_4$F${}_2$ with Separate Double Fe${}_2$As${}_2$ Layers
• Superconductivity coexisting with phase-separated static magnetic order in (Ba,K)Fe${}_2$As${}_2$, (Sr,Na)Fe${}_2$As${}_2$ and CaFe${}_2$As${}_2$
• Momentum-resolved superconducting gap in the bulk of Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ from combined ARPES and $\mu$SR measurements
• Doping evolution of superconducting gaps and electronic densities of states in Ba(Fe1-xCox)2As2 iron pnictides
• Two-gap superconductivity in Ba_1-xK_xFe_2As_2: A complementary study of the magnetic penetration depth by \muSR and ARPES
• Discovery of New Layered Iron Arsenide Superconductor (Ca,Pr)FeAs2
• Evolution of two-gap behavior of the superconductor FeSe_1-x
• Muon-spin rotation studies of SmFeAsO_0.85 and NdFeAsO_0.85 superconductors
• Searching for triplet superconductivity in the Quasi-One-Dimensional K2Cr3As3
• Universal observation of multiple order parameters in cuprate superconductors
• Enhancement of the superconducting gap by nesting in CaKFe4As4 - a new high temperature superconductor
• A New ZrCuSiAs-Type Superconductor: ThFeAsN
• Superconducting Properties of the $s^{\pm }$-wave state: Fe-based superconductors
• Crystal Structure and Superconductivity at about 30 K in $A$Ca${}_2$Fe${}_4$As${}_4$F${}_2$ ($A$ = Rb, Cs)
• Nodeless multiband superconductivity in stoichiometric single crystalline CaKFe${}_4$As${}_4$
• Time of life as it is in LiFeAs
• Magnetic fluctuations and superconducting properties of CaKFe4As4 studied by 75As NMR
• Direct evidence for the emergence of a pressure induced nodal superconducting gap in the iron-based superconductor Ba_0.65Rb_0.35Fe_2As_2
• Nodal multigap superconductivity in KCa${}_2$Fe${}_4$As${}_4$F${}_2$
• Two-gap superconductivity with line nodes in CsCa${}_2$Fe${}_4$As${}_4$F${}_2$
• Nodal superconducting gap structure in the quasi-one-dimensional Cs${}_2$Cr${}_3$As${}_3$ investigated using $\mu$SR measurements
• Signature of multigap nodeless superconductivity in CaKFe4As4
• Heat capacity jump at Tc and pressure derivatives of superconducting transition temperature in the Ba1-xKxFe2As2 (0.2 < x < 1.0) series
• Low superfluid density and possible multi-gap superconductivity in BiS2-based layered superconductor Bi4O4S3
• Probing the superconducting gap symmetry of PrRu${}_4$Sb${}_{12}$: A comparison with PrOs${}_4$Sb${}_{12}$
• Spin Resonance in the New-Structure-Type Iron-Based Superconductor CaKFe4As4
• Multigap superconductivity in ThAsFeN investigated using muSR measurements
• High-$T_{\mathrm{c}}$ superconductivity in undoped ThFeAsN
• Resistivity saturation in PrFeAsO${}_{1-x}$F${}_y$ superconductor: An evidence of strong electron-phonon coupling
• Investigations of the effect of nonmagnetic Ca substitution for magnetic Dy on spin-freezing in Dy2Ti2O7
• Evidence of nodal gap structure in the basal plane of the FeSe superconductor
• Nodal superconductivity coexists with low-moment static magnetism in single-crystalline tetragonal FeS: A muon spin relaxation and rotation study

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• Giant anisotropy in superconducting single crystals of CsCa${}_2$Fe${}_4$As${}_4$F${}_2$
• Single-crystal growth and extremely high H_c2 of 12442-type Fe-based superconductor KCa_2Fe_4As_4F_2
• Strong Pauli paramagnetic effect in the upper critical field of KCa${}_2$Fe${}_4$As${}_4$F${}_2$
• Multigap nodeless superconductivity in CsCa2Fe4As4F2 probed by heat transport
• Low temperature specific heat of 12442-type KCa_2Fe_4As_4F_2 single crystals
• Observation of a neutron spin resonance in the bilayered superconductor CsCa2Fe4As4F2
• Spectroscopic studies of the superconducting gap in the 12442 family of iron-based compounds
• Evidence of electron interaction with an unidentified bosonic mode in superconductor CsCa${}_2$Fe${}_4$As${}_4$F${}_2$
• The pairing symmetry in quasi-one-dimensional superconductor Rb2Mo3As3