Magnetic and superconducting phase diagram of Eu(Fe${}_{1-x}$Ni${}_x$)As${}_2$

Abstract

We report the Ni-doping effect on magnetism and superconductivity (SC) in an Eu-containing 112-type system Eu(Fe${}_{1-x}$Ni${}_x)$As${}_2$ ($0\le x\le 0.15$) by the measurements of resistivity, magnetization, and specific heat. The undoped EuFeAs${}_2$ undergoes a spin-density-wave (SDW) transition at $T_{\mathrm{SDW}}\sim$ 105 K in the Fe sublattice and a magnetic ordering at $T_{\mathrm{m}}\sim$ 40 K in the Eu sublattice. Complex Eu-spin magnetism is manifested by a spin-glass reentrance at $T_{\mathrm{SG}}\sim$ 15 K and an additional spin reorientation at $T_{\mathrm{SR}}\sim$ 7 K. With Ni doping, the SDW order is rapidly suppressed, and SC emerges in the Ni-doping range of 0.01 $\le x\le$ 0.1 where a maximum of the superconducting transition temperature $T_{\mathrm{c}}^{\max }=$ 17.6 K shows up at $x$ = 0.04. On the other hand, $T_{\mathrm{m}}$ decreases very slowly, yet $T_{\mathrm{SG}}$ and $T_{\mathrm{SR}}$ hardly change with the Ni doping. The phase diagram has been established, which suggests a very weak coupling between SC and Eu spins. The complex Eu-spin magnetism is discussed in terms of the Ruderman-Kittel-Kasuya-Yosida interactions mediated by the conduction electrons from both layers of FeAs and As surrounding Eu${}^{2+}$ ions.

arXiv comment10 pages, 7 figures; supplemental materials available on request

References in corpus (34)

• Superconductivity induced by Ni doping in BaFe${}_2$As${}_2$
• Superconductivity induced by phosphorus doping and its coexistence with ferromagnetism in EuFe${}_2$(As${}_{0.7}$P${}_{0.3}$)${}_2$
• Superconductivity in Ca1-xLaxFeAs2: A Novel 112-Type Iron Pnictide with Arsenic Zigzag Bonds
• Metamagnetic transition in EuFe${}_2$As${}_2$ single crystals
• Discovery of New Layered Iron Arsenide Superconductor (Ca,Pr)FeAs2
• Superconductivity and Ferromagnetism in Hole-Doped RbEuFe${}_4$As${}_4$
• Coexistence of Superconductivity and Ferromagnetism in P-doped EuFe2As2
• Narrow superconducting window in Ni-doped LaFeAsO
• Boundary-obstructed topological high-T${}_c$ superconductivity in iron pnictides
• A New Ferromagnetic Superconductor: CsEuFe${}_4$As${}_4$
• EuFe2(As1-xPx)2: reentrant spin glass and superconductivity
• The phase diagrams of iron-based superconductors: theory and experiments
• Suppression of spin-density-wave transition and emergence of ferromagnetic ordering of Eu${}^{2+}$ moments in EuFe${}_{2-x}$Ni${}_x$As${}_2$
• Superconductivity and ferromagnetism in EuFe${}_2$(As${}_{1-x}$P${}_x$)${}_2$
• CaFeAs${}_2$: a Staggered Intercalation of Quantum Spin Hall and High Temperature Superconductivity
• The effect of As-Chain layers in CaFeAs${}_2$
• Coexisting spin resonance and long-range magnetic order of Eu in EuRbFe${}_4$As${}_4$
• Synthesis and physical properties of Ca1-xRExFeAs2 with RE = La ~ Gd
• Magnetic structure of the Eu2+ moments in superconducting EuFe2(As1-xPx)2 with x = 0.19
• Significant contribution of As 4p orbitals to the low-lying electronic structure of 112-type iron-based superconductor Ca0.9La0.1FeAs2
• RbEu(Fe${}_{1-x}$Ni${}_x$)${}_4$As${}_4$: From a ferromagnetic superconductor to a superconducting ferromagnet
• Discovery of a novel 112-type iron-pnictide and La-doping induced superconductivity in Eu1-xLaxFeAs2 (x = 0 ~ 0.15)
• Coexistence of ferromagnetism and superconductivity in iron based pnictides: a time resolved magnetooptical study
• Co-co-doping effect for (Ca,RE)FeAs2 sintered bulk
• Coexistence of superconductivity and antiferromagnetism in Ca${}_{0.74(1)}$La${}_{0.26(1)}$(Fe${}_{1-x}$Co${}_x$)As${}_2$ single crystals
• Crystal growth and phase diagram of 112-type iron pnictide superconductor Ca1-yLayFe1-xNixAs2
• Superconductivity and Dirac Fermions in 112-phase Pnictides
• Spiral magnetic ordering of the Eu moments in EuNi${}_2$As${}_2$
• Evidence of Spontaneous Vortex Ground State in An Iron-Based Ferromagnetic Superconductor
• Helical Antiferromagnetic Ordering in EuNi{1.95}As2
• Observation of the anisotropic Dirac cone in the band dispersion of 112-structured iron-based superconductor Ca0.9La0.1FeAs2
• Self-induced Magnetic Flux Structure in the Magnetic Superconductor RbEuFe${}_4$As${}_4$
• Magnetism and superconductivity in Eu(Fe${}_{1-x}$Ni${}_x$)As${}_2$ ($x$ = 0, 0.04)
• Phase stability and large in-plane resistivity in the 112-type iron-based superconductor Ca${}_{1-x}$La${}_x$FeAs${}_2$