Identical effects of indirect and direct electron doping of superconducting BaFe2As2 thin films

Abstract

Electron doping of a 122-type iron pnictide BaFe2As2 by substituting the Ba site with an aliovalent ion (indirect doping), which had been unsuccessful by conventional solid-state synthesis methods, was achieved by a non-equilibrium film growth process. The substitution with La was substantiated by a systematic shrinkage of the c-axis lattice parameter due to the smaller ionic radius of La3+ than that of Ba2+. A negative Hall coefficient indicated that the majority carriers were electrons, as is consistent with this aliovalent ion doping. The La substitution suppressed an antiferromagnetic transition and induced bulk superconductivity at a maximum onset critical temperature (Tc) of 22.4 K. The electronic phase diagram for (Ba1-xLax)Fe2As2 was built, which revealed that the indirect electron doping at the Ba site with La [(Ba1-xLax)Fe2As2] exhibits almost the same Tc - doping level relation as that of the direct electron-doping at the Fe site with Co [Ba(Fe1-xCox)2As2]. This finding clarified that Tc in 122-type compounds is not affected by a crystallographic doping site, which is in sharp contrast to the 1111-type compounds, REFeAsO (RE = rare earth). It is tentatively attributed to the differences in their dimensionality of electronic structures and electron pairing symmetries.

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
• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• Magnetic order in BaFe2As2, the parent compound of the FeAs based superconductors in a new structural family
• Effects of Co substitution on thermodynamic and transport properties and anisotropic $H_{c2}$ in Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$ single crystals
• Superconductivity and Crystal Structures of (Ba1-xKx)Fe2As2 (x = 0 - 1)
• 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
• Effect of Co doping on superconductivity and transport properties in SmFe${}_{1-x}$Co${}_x$AsO
• Superconductivity induced by cobalt doping in iron-based oxyarsenides
• Structural collapse and superconductivity in rare earth-doped CaFe2As2
• AFe2As2 (A = Ca, Sr, Ba, Eu) and SrFe_(2-x)TM_(x)As2 (TM = Mn, Co, Ni): crystal structure, charge doping, magnetism and superconductivity
• The Unusual Superconducting State at 49 K in Electron-Doped CaFe2As2 at Ambient
• Hydrogen in layered iron arsenide: indirect electron doping to induce superconductivity
• Electronic Structure of Prototype AFe_2As_2 and ReOFeAs High-Temperature Superconductors: a Comparison
• Superconductivity in Epitaxial Thin Films of Co-Doped SrFe2As2 with Bilayered FeAs Structures and their Magnetic Anisotropy
• High Critical Current Density 4 MA/cm2 in Co-Doped BaFe2As2 Epitaxial Films Grown on (La, Sr)(Al, Ta)O3 Substrates without Buffer Layers
• Transport properties and superconductivity in $B{a}_{1-x}{M}_{x}F{e}_{2}A{s}_2$ (M=La and K) with double FeAs layers
• Phase diagram of iron-arsenide superconductors Ca(Fe1-xCox)2As2 (0 <= x <= 0.2)
• Transport and magnetic properties of Co-doped BaFe_{2}As_{2} epitaxial thin films

Cited by in corpus (18)

• Iron-Based Superconductors: current status of materials and pairing mechanism
• Exploration of new superconductors and functional materials and fabrication of superconducting tapes and wires of iron pnictides
• Thin Film Growth and Device Fabrication of Iron-Based Superconductors
• Thin film growth by pulsed laser deposition and properties of 122-type iron-based superconductor AE(Fe1--xCox)2As2 (AE = alkaline earth)
• A large moment antiferromagnetic order in overdoped high-Tc superconductor 154SmFeAsO1-xDx
• Superconductivity in Li-intercalated 1T-SnSe2 driven by electric-field gating
• Superconductivity in Uncollapsed Tetragonal LaFe2As2
• Enhancing the three-dimensional electronic structure in 1111-type iron arsenide superconductors by H-substitution
• Magnetic scattering and electron pair breaking by rare-earth-ion substitution in BaFe2As2 epitaxial films
• Unusual pressure effects on the superconductivity of indirectly electron-doped (Ba1-xLax)Fe2As2 epitaxial films
• Ambipolar suppression of superconductivity by ionic gating in optimally-doped BaFe2(As,P)2 ultrathin films
• Hydrogen-substituted superconductors SmFeAsO1-xHx misidentified as oxygen-deficient SmFeAsO1-x
• Superconducting Properties and Phase Diagram of Indirectly Electron-Doped (Sr1-xLax)Fe2As2 Epitaxial Films Grown by Pulsed Laser Deposition
• Lattice Parameters Guide Superconductivity in Iron-Arsenides
• Reversible Tuning of the Collapsed Tetragonal Phase Transition in CaFe2As2 by Separate Control of Chemical Pressure and Electron Doping
• Tunable superconductivity in Fe-pnictide heterointerfaces by diffusion control
• Phase transition in CaFeAsH: bridging 1111 and 122 iron-based superconductors
• Novel method to study strain effect of thin films using a piezoelectric-based device and a flexible metallic substrate