Related papers: Exchange integrals and magnetization distribution …
We have employed first principles calculations to study the electronic structure and magnetic properties of the low-dimensional phosphates, Ba2Cu(PO4)2 and Sr2Cu(PO4)2. Using the self-consistent tight-binding lin- earized muffin-tin orbital…
One of the remarkable properties of the II-VI diluted magnetic semiconductor (ZnMn)Se is the giant spin splitting of the valence band states under application of the magnetic field (giant Zeeman splitting). This splitting reveals strong…
The magnetic moments per Fe atom in high-$T{_\textrm{c}}$ iron-based superconducting compounds, BaFe$_{2}$As$_{2}$ and LaFeAsO obtained from the first-principles calculation with local-spin-density approximation are much larger than those…
Neutron diffraction and bulk measurements are used to determine the nature of the low-temperature ordered state in LiCu$_2$O$_2$, a $S=1/2$ spin-chain compound with competing interactions. The magnetic structure is found to be helimagnetic,…
Cu$_2$Fe$_2$Ge$_4$O$_{13}$ is a bicomponent compound that consists of Cu dimers and Fe chains with separate energy scale. By inelastic neutron scattering technique with high-energy resolution we observed the indirect Fe - Fe exchange…
Starting from a single band Hubbard model in the Wannier function basis, we revisit the problem of the ligand contribution to exchange and derive explicit formulae for the exchange integrals in metal oxide compounds in terms of atomic…
We report synthesis and magnetic properties of quasi-one-dimensional spin-$\frac{1}{2}$ Heisenberg antiferromagnetic chain compound BaNa$_2$Cu(VO$_4$)$_2$. This orthovanadate has a centrosymmetric crystal structure, $C2/c$, where the…
Neutron scattering studies on powder and single crystals have provided new evidences for unconventional magnetism in Cu2Te2O5Cl2. The compound is built from tetrahedral clusters of S=1/2 Cu2+ spins located on a tetragonal lattice. Magnetic…
The magnetic excitation spectrum and Hamiltonian of the quantum magnet BaCuTe2O6 is studied by inelastic neutron scattering (INS) and density functional theory (DFT). INS on powder and single crystal samples reveals overlapping spinon…
Magnetic excitations in a weakly coupled spin dimers and chains compound Cu2Fe2Ge4O13 are measured by inelastic neutron scattering. Both structure factors and dispersion of low energy excitations up to 10 meV energy transfer are well…
The structure and the magnetic properties of layered Li3Cu2SbO6 are investigated by powder X-ray diffraction, static susceptibility, and electron spin resonance studies up to 330 GHz. The XRD data experimentally verify the space group C2/m…
We report on band structure calculations and a microscopic model of the low-dimensional magnet beta-Cu2V2O7. Magnetic properties of this compound can be described by a spin-1/2 anisotropic honeycomb lattice model with the averaged coupling…
To understand spin interactions in materials of the Cu$_2$Sb structure type, inelastic neutron scattering of Fe$_2$As single crystals was examined at different temperatures and incident neutron energies. The experimental phonon spectra…
A well-known connection between the magnetic susceptibility and the effective exchange parameter is analyzed. It is shown that all current computational schemes use a long-wave approximation which is suitable only for localized moments…
Two-stage spin-flop transitions are observed the in quasi-one-dimensional antiferromagnet, BaCu${}_2$Si${}_2$O${}_7$. A magnetic field applied along the easy axis induces a spin-flop transition at 2.0 T followed by a second transition at…
The electronic and magnetic structure, including the Heisenberg model exchange interaction parameters, was explored for the recently proposed novel cuprate Cu$_2$F$_5$. Using the DFT+U calculation, it is shown that the compound is formed by…
The calculation of interatomic magnetic exchange interactions entering the Heisenberg model from the standpoint of the density functional theory (DFT) is outlined for two Fe-based molecular magnets: a trinuclear complex with a Schiff base…
A clear physics picture of TbBaCo$_{2}$O$_{5.5}$ is revealed on the basis of density functional theory calculations. An antiferromagnetic (AFM) superexchange coupling between the almost high-spin Co$^{3+}$ ions competes with a ferromagnetic…
The antiferromagnetic insulating cuprate Ba$_3$Cu$_2$O$_4$Cl$_2$ contains folded CuO$_2$ chains with four magnetic copper ions ($S=1/2$) per unit cell. An underlying multiorbital Hubbard model is formulated and the superexchange theory is…
We observed in superconducting (Tl,Rb)2Fe4Se5 spin-wave branches that span an energy range from 6.5 to 209 meV. Spin dynamics are successfully described by a Heisenberg localized spin model whose dominant in-plane interactions include only…