Hidden magnetic order in CuNCN

Abstract

We report a comprehensive experimental and theoretical study of the quasi-one-dimensional quantum magnet CuNCN. Based on magnetization measurements above room temperature as well as muon spin rotation and electron spin resonance measurements, we unequivocally establish the localized Cu+2-based magnetism and the magnetic transition around 70 K, both controversially discussed in the previous literature. Thermodynamic data conform to the uniform-spin-chain model with a nearest-neighbor intrachain coupling of about 2300 K, in remarkable agreement with the microscopic magnetic model based on density functional theory band-structure calculations. Using exact diagonalization and the coupled-cluster method, we derive a collinear antiferromagnetic order with a strongly reduced ordered moment of about 0.4 mu_B, indicating strong quantum fluctuations inherent to this quasi-one-dimensional spin system. We re-analyze the available neutron-scattering data, and conclude that they are not sufficient to resolve or disprove the magnetic order in CuNCN. By contrast, spectroscopic techniques indeed show signatures of long-range magnetic order below 70 K, yet with a rather broad distribution of internal field probed by implanted muons. We contemplate the possible structural origin of this effect and emphasize peculiar features of the microstructure studied with synchrotron powder x-ray diffraction.

arXiv comment17 pages, 17 figures, 1 table

References in corpus (45)

• The ALPS project release 1.3: open source software for strongly correlated systems
• Thermodynamics of Spin S = 1/2 Antiferromagnetic Uniform and Alternating-Exchange Heisenberg Chains
• Finite-Size Scaling of the Ground State Parameters of the Two-Dimensional Heisenberg Model
• Stretched Exponential Relaxation Arising from a Continuous Sum of Exponential Decays
• Spin-polarized muons in condensed matter physics
• Dynamics of coupled quantum spin chains
• Cluster algorithms for general-S quantum spin systems
• Neel Temperature of Quasi-Low-Dimensional Heisenberg Antiferromagnets
• Ground-state phases of the spin-1/2 J_1-J_2 Heisenberg antiferromagnet on the square lattice: A high-order coupled cluster treatment
• Reduction of ordered moment and Neel temperature of quasi one-dimensional antiferromagnets Sr2CuO3 and Ca2CuO3
• Specific heat of quasi-2D antiferromagnetic Heisenberg models with varying inter-planar couplings
• An efficient implementation of high-order coupled-cluster techniques applied to quantum magnets
• Multi-Chain Mean-Field Theory of Quasi One-Dimensional Quantum Spin Systems
• Exchange interactions and magnetic properties of the layered vanadates CaV2O5, MgV2O5, CaV3O7 and CaV4O9
• Electronic structure and magnetic properties of the linear chain cuprates Sr_2CuO_3 and Ca_2CuO_3
• 17O NMR study of q=0 spin excitations in a nearly ideal S=1/2 1D Heisenberg antiferromagnet, Sr2CuO3, up to 800 K
• Magnetic order in the quasi-one-dimensional spin 1/2 chain, copper pyrazine dinitrate
• Realization of a large J_2 quasi-2D spin-half Heisenberg system: Li2VOSiO4
• Coupled Cluster Treatment of the Shastry-Sutherland Antiferromagnet
• Monte Carlo Study of the S=1/2 and S=1 Heisenberg Antiferromagnet on a Spatially Anisotropic Square Lattice
• High-Order Coupled Cluster Method Calculations for the Ground- and Excited-State Properties of the Spin-Half XXZ Model
• Frustrated spin-1/2 square lattice in the layered perovskite PbVO(3)
• A Plane of Weakly Coupled Heisenberg Chains: Theoretical Arguments and Numerical Calculations
• The frustrated spin-1/2 J1-J2 Heisenberg ferromagnet on the square lattice: Exact diagonalization and Coupled-Cluster study
• Magnetic order in the S=1/2 two-dimensional molecular antiferromagnet, copper pyrazine perchlorate Cu(Pz)_2(ClO_4)_2
• The quantum $J_1$--$J_1^{\prime }$--$J_2$ spin-1 Heisenberg model: Influence of the interchain coupling on the ground-state magnetic ordering in 2D
• Sr${}_2$Cu(PO${}_4$)${}_2$: A real material realization of the 1D nearest neighbor Heisenberg chain
• Sr2V3O9 and Ba2V3O9: quasi one-dimensional spin-systems with an anomalous low temperature susceptibility
• Halogen-mediated exchange in the coupled-tetrahedra quantum spin systems Cu2Te2O5X2 (X=Br,Cl)
• Weakly Coupled Antiferromagnetic Quantum Spin Chains
• Influence of an inter-chain coupling on spiral ground-state correlations in frustrated spin-1/2 J1-J2 Heisenberg chains
• Electronic structure and magnetic properties of the spin-1/2 Heisenberg system CuSe2O5
• Spin correlations and exchange in square lattice frustrated ferromagnets
• Single Crystal Growth, Crystallography, Magnetic Susceptibility, Heat Capacity, and Thermal Expansion of the Antiferromagnetic S = 1 Chain Compound CaV2O4
• Large quantum fluctuations in the strongly coupled spin-1/2 chains of green dioptase: a hidden message from birds and trees
• Fluctuations and correlations in a frustrated S=1/2 square lattice with competing ferromagnetic and antiferromagnetic interactions: a muSR study
• Unconventional Magnetism in a Nitrogen-Based Analogue of Cupric Oxide
• ^{17}O and ^{51}V NMR for the zigzag spin-1 chain compound CaV2O4
• Local Magnetic Susceptibility of the Positive Muon in the Quasi 1D S=1/2 Antiferromagnet dichlorobis (pyridine) copper (II)
• Ab initio modeling of Bose-Einstein condensation in Pb2V3O9
• Uniform spin chain physics arising from NCN bridges in CuNCN: surprises on the way from copper oxides to their nitride analogs
• Frustrated Quantum Antiferromagnets: Application of High-Order Coupled Cluster Method
• Antiferromagnetic spin-1/2 chains in (NO)Cu(NO3)3: a microscopic study
• Impurity-induced singlet breaking in SrCu2(BO3)2
• Ground-state long-range order in quasi-one-dimensional Heisenberg quantum antiferromagnets: High-order coupled-cluster calculations

Cited by in corpus (6)

• Magnetism of CuX2 frustrated chains (X = F, Cl, Br): the role of covalency
• Magnetism of coupled spin tetrahedra in ilinskite-type KCu${}_5$O${}_2$(SeO${}_3$)${}_2$Cl${}_3$
• Hidden orders in spin-orbit entangled correlated insulators
• Hidden Magnetic Order in Triangular-Lattice Magnet Li2MnTeO6
• Magnetic inhomogeneity in the copper pseudochalcogenide CuNCN
• c-a-ca Mean Field RVB Model of CuNCN Physics. Structure Manifestations of the RVB Transitions