Ferromagnetic cluster-glass phase in Ca(Co,Ir)2As2 crystals

Abstract

Single crystals of Ca[Co_(2-x)Ir_(x)]_(2-y)As2 with 0 <= x <= 0.35 and 0.10 <= y <= 0.14 have been grown using the self-flux technique and characterized by single-crystal x-ray diffraction (XRD), energy-dispersive x-ray spectroscopy, magnetization M and magnetic susceptibility chi measurements versus temperature T, magnetic field H, and time t, and heat capacity Cp(H,T) measurements. The XRD refinements reveal that all the Ir-substituted crystals crystallize in a collapsed-tetragonal structure as does the parent CaCo_(2-y)As2 compound. A small 3.3% Ir substitution for Co in CaCo_(1.86)As2 drastically lowers the A-type antiferromagnetic (AFM) transition temperature TN from 52 to 23 K with a significant enhancement of the Sommerfeld electronic heat-capacity coefficient. The positive Weiss temperatures obtained from Curie-Weiss fits to the chi(T>TN) data indicate that the dominant magnetic interactions are ferromagnetic (FM) for all x. A magnetic phase boundary is inferred to be present between x = 0.14 and x = 0.17 from a discontinuity in the x dependences of the effective moment and Weiss temperature in the Curie-Weiss fits. FM fluctuations that strongly increase with increasing x are also revealed from the chi(T) data. The magnetic ground state for x >= 0.17 is a spin glass as indicated by hysteresis in chi(T) between field-cooling and zero-field-cooling measurements and from the relaxation of M in a small field that exhibits a stretched-exponential time dependence. The spin glass has a small FM component to the ordering and is hence inferred to be comprised of small FM clusters. A logarithmic T dependence of Cp at low T for x = 0.14 is consistent with the presence of significant FM quantum fluctuations. This composition is near the T = 0 boundary at x = 0.16 between the A-type AFM phase containing ferromagnetically-aligned layers of spins and the FM cluster-glass phase.

arXiv comment16 pages, 18 captioned figures, 6 tables, 68 references

References in corpus (49)

• Superconductivity at 38 K in the iron arsenide (Ba1-xKx)Fe2As2
• The Puzzle of High Temperature Superconductivity in Layered Iron Pnictides and Chalcogenides
• Superconductivity in Iron Compounds
• High-temperature superconductivity in iron-based materials
• A Common Thread: the pairing interaction for the unconventional superconductors
• $\alpha$-RuCl3: a Spin-Orbit Assisted Mott Insulator on a Honeycomb Lattice
• Superconductivity up to 37 K in (A1-xSrx)Fe2As2 with A=K and Cs
• Antiferromagnetic order and spin dynamics in iron-based superconductors
• Magnetism and its microscopic origin in iron-based high-temperature superconductors
• Superconductivity and spin-orbit coupling in non-centrosymmetric materials: a review
• Stretched Exponential Relaxation Arising from a Continuous Sum of Exponential Decays
• FeAs-based superconductivity: a case study of the effects of transition metal doping on BaFe2As2
• Superconductivity and Crystal Structures of (Ba1-xKx)Fe2As2 (x = 0 - 1)
• Pressure-induced volume-collapsed tetragonal phase of CaFe2As2 as seen via neutron scattering
• The Unexpected Properties of Alkali Metal Iron Selenide Superconductors
• Superconductivity induced by phosphorus doping and its coexistence with ferromagnetism in EuFe${}_2$(As${}_{0.7}$P${}_{0.3}$)${}_2$
• Superconductivity in SrFe_(2-x)Co_xAs_2: Internal Doping of the Iron Arsenide Layers
• Unconventional pairing in the iron arsenide superconductors
• Magnetic relaxation phenomena and cluster glass properties of La{0.7-x}Y{x}Ca{0.3}MnO{3} manganites
• Ferromagnetic cluster spin-glass behavior in PrRhSn3
• Lattice collapse and quenching of magnetism in CaFe2As2 under pressure: A single crystal neutron and x-ray diffraction investigation
• The role of spin-orbit coupling for the superconducting state in Sr_2RuO_4
• Renormalized behavior and proximity to a magnetic quantum critical point in BaCo${}_2$As${}_2$
• Role of spin-orbit coupling and evolution of the electronic structure of WTe${}_2$ under an external magnetic field
• Crystallographic, Electronic, Thermal and Magnetic Properties of Single-Crystal SrCo2As2
• Crystal Growth and Physical Properties of SrCu2As2, SrCu2Sb2 and BaCu2Sb2
• Two successive field-induced spin-flop transitions in single-crystalline CaCo${}_2$As${}_2$
• Stripe Antiferromagnetic Spin Fluctuations in SrCo${}_2$As${}_2$
• Crystal and Magnetic Structure of CaCo{1.86}As2 Studied by X-ray and Neutron Diffraction
• Physical Properties of Metallic Antiferromagnetic CaCo{1.86}As2 Single Crystals
• Avoided ferromagnetic quantum critical point: Unusual short-range ordered state in CeFePO
• Prominent role of spin-orbit coupling in FeSe
• Evolution of the bulk properties, structure, magnetic order, and superconductivity with Ni doping in CaFe2-xNixAs2
• Competing Magnetic Fluctuations in Iron Pnictide Superconductors: Role of Ferromagnetic Spin Correlations Revealed by NMR
• Bulk Superconductivity at 2.6 K in Undoped RbFe_2As_2
• Metamagnetic transition in Ca${}_{1-x}$Sr${}_x$Co${}_2$As${}_2$($x$ = 0 and 0.1) single crystals
• Effective One-Dimensional Coupling in the Highly-Frustrated Square-Lattice Itinerant Magnet CaCo${}_{2-y}$As${}_2$
• Avoided ferromagnetic quantum critical point in CeRuPO
• Coexistence of ferromagnetic and stripe antiferromagnetic spin fluctuations in SrCo${}_2$As${}_2$
• Crystallography and Physical Properties of BaCo2As2, Ba{0.94}K{0.06}Co2As2 and Ba{0.78}K{0.22}Co2As2
• Non-Fermi-liquid behaviors associated with a magnetic quantum-critical point in Sr(Co{1-x}Ni{x})2As2 single crystals
• Pressure-induced unconventional superconductivity near a quantum critical point in CaFe2As2
• Flat band magnetism and helical magnetic order in Ni-doped SrCo${}_2$As${}_2$
• Competing magnetic phases and itinerant magnetic frustration in SrCo${}_2$As${}_2$
• Anomalous Composition-Induced Crossover in the Magnetic Properties of the Itinerant-Electron Antiferromagnet Ca{1-x}Sr{x}Co{2-y}As{2}
• Helical magnetic ordering in Sr(Co1-xNix)2As2
• Suppression of magnetic order in CaCo${}_{1.86}$As${}_2$ with Fe substitution: Magnetization, neutron diffraction, and x-ray diffraction studies of Ca(Co${}_{1-x}$Fe${}_x$)${}_y$As${}_2$
• Antiferromagnetic Stacking of Ferromagnetic Layers and Doping Controlled Phase Competition in Ca${}_{1-x}$Sr${}_x$Co${}_{2-y}$As${}_2$
• Coexistence of antiferromagnetic and ferromagnetic spin correlations in SrCo2As2 revealed by 59Co and 75As NMR

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• Chemical tuning of a honeycomb magnet through a critical point
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• Carrier Tuning of Stoner Ferromagnetism in ThCr${}_2$Si${}_2$-Structure Cobalt Arsenides
• Cluster glass behavior and magnetocaloric effect in the hexagonal polymorph of disordered Ce${}_2$PdGe${}_3$
• Emergence of ferromagnetism due to Ir substitutions in single-crystalline Ba[Co(1 x)Ir(x)]2As2