Magnetic properties of LiCu${}_3$O${}_3$ -- quasi-two-dimensional antiferromagnet on depleted square lattice

Abstract

LiCu${}_3$O${}_3$ is a novel 2D S=1/2 antiferromagnet with randomly depleted square lattice. The crystal structure contains two types of square planes with different Cu${}^{2+}\to$ Li${}^{+}$ substitution rates (20% and 40%). ${}^7$Li NMR and magnetization measurements performed on single crystals of LiCu${}_3$O${}_3$ revealed the occurrence of magnetic order at $T_{c1}=123$ K and the change of the magnetic state at $T_{c2}\approx 30$ K. The high temperature transition can be attributed to establishment of magnetic order in planes with higher concentration of magnetic ions and the low temperature transition -- to the magnetic ordering in planes with lower concentration of magnetic ions. Broad continuous NMR spectra below $T_{c1}$ reflect a continuous distribution of values or directions of magnetic moments in LiCu${}_3$O${}_3$ typical for spiral, spin-modulated magnetic structures or structures with frozen disorder. Magnetization measurements revealed a spin-flop transition which indicates weak uniaxial anisotropy of the spin structure. Relatively small value of magnetic susceptibility at all orientations of applied magnetic field shows that magnetic structure is rigid, since the estimated value of saturation field derived from differential susceptibility measured at ${\mu }_{0}H=5$ T is ${\mu }_0{H}_{sat}\approx$200 T.

arXiv comment11 pages, 12 figures

References in corpus (18)

• Li${}_2$VO(Si,Ge)O${}_4$, a prototype of a two-dimensional frustrated quantum Heisenberg antiferromagnet
• Reduction of ordered moment and Neel temperature of quasi one-dimensional antiferromagnets Sr2CuO3 and Ca2CuO3
• Quantum Impurities in the Two-Dimensional Spin One-Half Heisenberg Antiferromagnet
• Classical percolation transition in the diluted two-dimensional S=1/2 Heisenberg antiferromagnet
• Magnetic and thermodynamic properties of Li(2)VOSiO(4): a two-dimensional S=1/2 frustrated antiferromagnet on a square lattice
• Spin waves and magnetic interactions in LiCu2O2
• Spin-modulated quasi-1D antiferromagnet LiCuVO_4
• Quantum Phase Transition of Randomly-Diluted Heisenberg Antiferromagnet on a Square Lattice
• Diluted quantum antiferromagnets: spin excitations and long-range order
• NMR study of the high-field magnetic phase of LiCuVO${}_4$
• Spin Dilution in Frustrated Two-Dimensional s=1/2 Antiferromagnets on a Square Lattice
• Evidence for impurity-induced frustration in La2CuO4
• Impurity-induced frustration: low-energy model of diluted oxides
• Magnetic structure and domain conversion of quasi-2D frustrated antiferromagnet CuCrO2 probed by NMR
• Spin glass state and enhanced spiral phase in doped delafossite oxide CuCrO2
• Search for a nematic phase in quasi-2D antiferromagnet CuCrO2 by NMR in electric field
• Continuous transformation between ferro and antiferro circular structures in $J_1-J_2-J_3$ frustrated Heisenberg model
• Magnetic resonance in the quasi-2D square lattice easy-plane antiferromagnet Ba${}_2$MnGe${}_2$O${}_7$