Related papers: Magnetic model for A2CuP2O7 (A = Na, Li) revisited…
Na$_x$CoO$_2$, the parent compound of the recently synthesized superconductor Na$_x$CoO$_2$:$y$H$_2$O, exhibits bulk antiferromagnetic order below $\sim20$ K for 0.75 $\leq x \leq$ 0.9. We have performed neutron scattering experiments in…
We present a microscopic model of the spin-gap quantum magnet (CuCl)LaNb2O7 that was previously suggested as a realization of the spin-1/2 frustrated square lattice. Taking advantage of the precise atomic positions from recent crystal…
The object of this work is to study the magnetic properties of the Lieb structure based on magnetic particles with core-shell nano-structure. This system is consisting of a ferromagnetic 2D Ising model formed with spins: sigma=1/2, S=1 and…
We present neutron diffraction, muon spin rotation and pulsed-field magnetometry measurements on the Heisenberg quantum chiral chain [Cu(pym)(H2O)4]SiF6.H2O, which displays a four-fold-periodic rotation of the local environment around the…
Based on density functional theory band structure calculations, quantum Monte-Carlo simulations, and high-field magnetization measurements, we address the microscopic magnetic model of BaAg2Cu[VO4]2 that was recently proposed as a spin-1/2…
The magnetic structures and spin dynamics of Na$_{2}$Co$_{2}$TeO$_{6}$ and Na$_{2}$Ni$_{2}$TeO$_{6}$ are investigated by means of elastic and inelastic neutron scattering measurements and the results are discussed in the context of a…
We present evidence that crystalline Sr_2Cu(PO_4)_2 is a nearly perfect one-dimensional (1D) spin-1/2 anti-ferromagnetic Heisenberg model (AHM) chain compound with nearest neighbor only exchange. We undertake a broad theoretical study of…
By means of density functional theory (DFT) calculations (with and without inclusion of spin-orbit (SO) coupling) we present a detailed study of the electronic structure and corresponding microscopic Hamiltonian parameters of Na2IrO3. In…
Inelastic neutron scattering experiments are performed on a nanoporous metal complex Cu-Trans-1,4-Cyclohexanedicarboxylic Acid (Cu-CHD) adsorbing O2 molecules to identify the spin model of the O2-based magnet realized in the host complex.…
The Kitaev spin model offers an exact quantum spin liquid in the ground state, which has stimulated exploration of its material realization over the last decade. Thus far, most of the candidates are found in $4d$- and $5d$-electron…
The results of ac and dc magnetization and heat capacity measurements as a function of temperature (T = 1.8 to 300 K) are reported for a quasi-one-dimensional compound, Ca$_3$CuMnO$_6$, crystallizing in a triclinically distorted…
Honeycomb iridate Na2IrO3, a Jeff=1/2 magnet, is a potential platform for realizing the quantum spin liquid. Many experiments have shown that its magnetic ground state has a zigzag antiferromagnetic (AFM) order. However, there is still a…
A new spin-1/2 quasi-one-dimensional antiferromagnet KCuMoO_4(OH) is prepared by the hydrothermal method. The crystal structures of KCuMoO_4(OH) and the already-known Na-analogue, NaCuMoO_4(OH), are isotypic, comprising chains of Cu^{2+}…
Magnetic excitations in an array of (VO)_2P_2O_7 single crystals have been measured using inelastic neutron scattering. Until now, (VO)_2P_2O_7 has been thought of as a two-leg antiferromagnetic Heisenberg spin ladder with chains running in…
Induced by quenched disorder, random-singlet states occur in a variety of low-dimensional spin-1/2 antiferromagnets, some of them candidates for quantum spin liquids. Here we report measurements of the specific heat, magnetization, and…
The puzzle of 3D magnetic interactions in the structurally 2D layered oxide Na$_{x}$CoO$_2$ is addressed using first principles calculations and analysis of the exchange mechanisms. The calculations agree with recent neutron results,…
We consider the quasi-two-dimensional pseudo-spin-1/2 Kitaev - Heisenberg model proposed for A2IrO3 (A=Li, Na) compounds. The spin-wave excitation spectrum, the sublattice magnetization, and the transition temperatures are calculated in the…
The magnetic properties of the two isostructural molecule-based magnets, Ni(NCS)$_{2}$(thiourea)$_{2}$, $S$ = 1, [thiourea = SC(NH$_2$)$_2$] and Co(NCS)$_{2}$(thiourea)$_{2}$, $S$ = 3/2, are characterised using several techniques in order…
We calculate the Raman spectrum of the two-dimensional (2D) spin-1/2 Heisenberg antiferromagnet by exact diagonalization and quantum Monte Carlo techniques on clusters of up to 144 sites and, on a 16-site cluster, by considering the…
High field mangetization, field-dependent specific heat measurements, and zero field inelastic magnetic neutron scattering have been used to explore the magnetic properties of copper pyrazine dinitrate (Cu(C4H4N2)(NO3)2). The material is an…