Quasi-two-dimensional $S=1/2$ magnetism of Cu[C${}_6$H${}_2$(COO)${}_4$][C${}_2$H${}_5$NH${}_3$]${}_2$

Abstract

We report structural and magnetic properties of the spin-$\frac{1}{2}$ quantum antiferromagnet Cu[C${}_6$H${}_2$(COO)${}_4$][C${}_2$H${}_5$NH${}_3$]${}_2$ by means of single-crystal x-ray diffraction, magnetization, heat capacity, and electron spin resonance (ESR) measurements on polycrystalline samples, as well as band-structure calculations. The triclinic crystal structure of this compound features CuO${}_4$ plaquette units connected into a two-dimensional framework through anions of the pyromellitic acid [C${}_6$H${}_2$(COO)${}_4$]${}^{4-}$. The ethylamine cations [C${}_2$H${}_5$NH${}_3{]}^{+}$ are located between the layers and act as spacers. Magnetic susceptibility and heat capacity measurements establish a quasi-two-dimensional, weakly anisotropic and non-frustrated spin-$\frac{1}{2}$ square lattice with the ratio of the couplings $J_a/J_c\simeq 0.7$ along the $a$ and $c$ directions, respectively. No clear signatures of the long-range magnetic order are seen in thermodynamic measurements down to 1.8\,K. However, the gradual broadening of the ESR line suggests that magnetic ordering occurs at lower temperatures. Leading magnetic couplings are mediated by the organic anion of the pyromellitic acid and exhibit a non-trivial dependence on the Cu--Cu distance, with the stronger coupling between those Cu atoms that are further apart.

arXiv comment10 pages, 10 figures, 5 tables

References in corpus (28)

• The ALPS project release 1.3: open source software for strongly correlated systems
• Cluster algorithms for general-S quantum spin systems
• Generalized Directed Loop Method for Quantum Monte Carlo Simulations
• Neel Temperature of Quasi-Low-Dimensional Heisenberg Antiferromagnets
• From high temperature supercondutivity to quantum spin liquid: progress in strong correlation physics
• Magnetic properties of BaCdVO(PO_4)_2: a strongly frustrated spin-1/2 square lattice close to the quantum critical regime
• Magnetocaloric effect and magnetic cooling near a field-induced quantum-critical point
• Extension of the spin-1/2 frustrated square lattice model: the case of layered vanadium phosphates
• Phase separation and frustrated square lattice magnetism of Na1.5VOPO4F0.5
• 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
• The Two-Dimensional Square-Lattice S=1/2 Antiferromagnet Cu(pz)${}_2$(ClO${}_4$)${}_2$
• The spin gap in malachite Cu2(OH)2CO3 and its evolution under pressure
• Dimensionality selection in a molecule-based magnet
• Frustrated local moment models for Fe-pnictide magnetism
• Peculiar long-range superexchange in Cu2A2O7 (A = P, As, V) as a key element of the microscopic magnetic model
• Quantum effects in a weakly-frustrated S=1/2 two-dimensional Heisenberg antiferromagnet in an applied magnetic field
• Second-order quantum corrections for the frustrated, spatially anisotropic, spin-1/2 Heisenberg antiferromagnet on a square lattice
• Hindered magnetic order from mixed dimensionalities in CuP${}_2$O${}_6$
• Pressure-induced quantum critical and multicritical points in a frustrated spin liquid
• Magnetic model for A2CuP2O7 (A = Na, Li) revisited: 1D versus 2D behavior
• Square-lattice magnetism of diaboleite Pb2Cu(OH)4Cl2
• Magnetization and spin dynamics of the spin S=1/2 hourglass nanomagnet Cu5(OH)2(NIPA)4*10H2O
• Crystals for neutron scattering studies of quantum magnetism
• Decorated Shastry-Sutherland lattice in the spin-1/2 magnet CdCu2(BO3)2
• Ordered moment in the anisotropic and frustrated square lattice Heisenberg model
• Magnetic-field induced multiferroicity in a quantum critical frustrated spin liquid
• Staggered moment dependence on field-tuned quantum fluctuations in 2D frustrated antiferromagnets

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