Related papers: Antiferromagnetic Heisenberg S=5/2 spin chain comp…
Magnetism of the $S$ = 1 Heisenberg antiferromagnets on the spatially anisotropic square lattice has been scarcely explored. Here we report a study of the magnetism, specific heat, and thermal conductivity on Ni[SC(NH$_2$)$_2$]$_6$Br$_2$…
Crystallographic, electronic transport, thermal and magnetic properties are reported for SrMn2As2 and CaMn2As2 single crystals grown using Sn flux. Rietveld refinements of powder x-ray diffraction data show that the two compounds are…
Magnetic correlations of two iso-structural quasi-one-dimensional (1D) antiferromagnetic spin-chain compounds Sr$M_2$V$_2$O$_8$ ($M$ = Co, Mn) have been investigated by magnetization and powder neutron diffraction. Two different collinear…
The ferrimagnetic spin-1/2 chain composed of alternating Ising and Heisenberg spins in an arbitrarily oriented magnetic field is exactly solved using the spin-rotation transformation and the transfer-matrix method. It is shown that the…
We present specific-heat and neutron-scattering results for the \emph{S}=1/2 quantum antiferromagnet (dimethylammonium)(3,5-dimethylpyridinium)CuBr$_4$. The material orders magnetically at \emph{T}$_N$=1.99(2)\,K, and magnetic excitations…
We present a model compound for the $S$=1/2 ferromagnetic Heisenberg chain composed of the verdazyl-based complex $[$Zn(hfac)$_2]$$[$4-Cl-$o$-Py-V-(4-F)$_2]$. $Ab$ $initio$ MO calculations indicate a predominant ferromagnetic interaction…
Ground-state and thermodynamic properties of the one-dimensional Heisenberg antiferromagnet in which two S=1/2 and two S=1 spins are arranged alternatively are studied by a quantum Monte Carlo method and by analytical estimates. It is found…
The magnetic state of the single-component molecular compound, [Cu(tmdt)$_{2}$], is investigated by means of $^{1}$H-NMR. An abrupt spectral broadening below 13 K and a sharp peak in nuclear spin-lattice relaxation rate, $T_{1}^{-1}$, at 13…
Motivated by recent experimental progress in the quasi-one-dimensional quantum magnet NiNb$_2$O$_6$, we study the spin dynamics of an S=1 ferromagnetic Heisenberg chain with single-ion anisotropy by using a semiclassical molecular dynamics…
SrEr$_2$O$_4$ has been characterised by low-temperature powder neutron diffraction, as well as single crystal specific heat and magnetisation measurements. Magnetisation measurements show that the magnetic system is highly anisotropic at…
Hexagonal HoMnO$_{3}$ is a frustrated antiferromagnet (T$_{N}$=72 K) ferroelectric (T$_{C}$=875 K) in which these two order parameters are coupled. Our neutron measurements of the spin wave dispersion for the S=2 Mn$^{3+}$ on the layered…
The magnetic susceptibility and magnetization of two new layered S=1/2 Heisenberg antiferromagnets with moderate exchange are reported. The two isostructural compounds, (2-amino-5-chloropyridinium)2CuBr4 ((5CAP)2CuBr4) and…
The ordering of weakly coupled random antiferromagnetic $S=1/2$ chains, as relevant for recent experimentally investigated spin chain materials, is considered theoretically. The one-dimensional isotropic Heisenberg model with random…
Motivated by recent observation of a new high field phase near saturation in chromium spinels $A$Cr$_2$O$_4$ ($A=$ Zn, Cd, Hg), we study the $S = 3/2$ pyrochlore Heisenberg antiferromagnet with biquadratic interactions. Magnon instability…
Magnetization and neutron diffraction measurements indicate long-range antiferromagnetic ordering below TN=4 K in the 2D, S=1/2 Heisenberg antiferromagnet K2V3O8. The ordered state exhibits ``weak ferromagnetism'' and novel, field-induced…
Muon spin rotation technique is used to study magnetic ordering in ultra-pure samples of SrCu$_{1-x}$Ni$_x$O$_2$, an archetypical $S=1/2$ antiferromagnetic Heisenberg chain system with a small amount of $S=1$ defects. The ordered state in…
The magnetization process of the one-dimensional antiferromagnetic Heisenberg model with the Ising-like anisotropic exchange interaction is studied by the exact diagonalization technique. It results in the evidence of the first-order spin…
Magnetic properties of AMoOPO$_4$Cl (A = K, Rb) with Mo$^{5+}$ ions in the 4$d^1$ electronic configuration are investigated by magnetization, heat capacity and NMR measurements on single crystals, combined with powder neutron diffraction…
We report on the synthesis of a new $\gamma$-phase of the spin $S$~=~$\frac{3}{2}$ compound SrCo$_2$(PO$_4$)$_2$ together with a detailed structural, magnetic and thermodynamic properties. The $\gamma$-phase of SrCo$_2$(PO$_4$)$_2$…
We report first-principles all-electron density-functional based studies of the electronic structure, magnetic ordering and anisotropy for the V$_{15}$ molecular magnet. From these calculations, we determine a Heisenberg Hamiltonian with…