相关论文: Exchange in the linear cuprate antiferromagnets Sr…

Data from susceptibility measurements on Sr_2CuO_3 are compared with recent theoretical predictions for the magnetic susceptibility of the antiferromagnetic spin-1/2 Heisenberg chain. The experimental data fully confirms the theoretical…

We report ab initio quantum chemical cluster calculations of the chain (J_a) and the largest interchain (J_b) Heisenberg exchange of the chain cuprates Ca_2CuO_3 and Sr_2CuO_3. We find that J_a is comparable to the in-plane J in layered…

Sr_2CuO_3 and Ca_2CuO_3 are considered to be model systems of strongly anisotropic, spin-1/2 Heisenberg antiferromagnets. We report on the basis of a band-structure analysis within the local density approximation and on the basis of…

We report on the microscopic model of the recently synthesized one-dimensional quantum magnet (NO)Cu(NO3)3. Applying density functional theory band structure calculations, we obtain a leading antiferromagnetic exchange coupling J ~ 200 K,…

We report elastic neutron diffraction and muon spin relaxation (muSR) measurements of the quasi one-dimensional antiferromagnets Sr2CuO3 and Ca2CuO3, which have extraordinarily reduced TN/J ratios. We observe almost resolution-limited…

We report single crystal growth and magnetic susceptibility and neutron diffraction studies of the S=1/2 quasi-1D antiferromagnet CaCu2O3. The structure of this material is similar to that of the prototype two-leg spin-ladder compound…

Ac and dc magnetization and heat-capacity (C) measurements performed on the pseudo-one-dimensional compound Sr$_3$CuIrO$_6$ reveal a competition between antiferromagnetic (AF) and ferromagnetic (F) exchange couplings, as evidenced by…

A combination of magnetic heat capacity measurements versus temperature under multiple fixed external fields using a polycrystalline sample, plus easy and hard axis aligned magnetization versus field measurements using a single crystal of…

Experimental data for the magnetic susceptibility and magnetostriction of CuGeO_3 are analyzed within a one-dimensional antiferromagnetic model with nearest ({J_1}) and next-nearest neighbour interactions ({J_2}). We show that the ratio of…

We present a theoretical and experimental study of a quasi-one-dimensional zigzag antiferromagnet (N_2H_5)CuCl_3, which can be viewed as weakly coupled Heisenberg chains with a frustrated interaction. We first discuss generic features of…

We calculate the Heisenberg exchange J in the quasi-2D antiferromagnetic cuprates La2CuO4, YBa2Cu3O6, Nd2CuO4 and Sr2CuO2Cl2. We apply all-electron (MC)SCF and non-orthogonal CI calculations to [Cu2O11]18-, [Cu2O9]14-, [Cu2O7]10- and…

From experimental and theoretical analyses of magnetic and specific-heat properties, we present the complete magnetic phase diagram of the quasi-one-dimensional antiferromagnet Cu(N$_2$H$_5$)$_2$(SO$_4$)$_2$. On cooling and at zero magnetic…

We perform first-principles calculations of multiferroic Ca$_3$CoMnO$_6$ and evaluate the exchange coupling constants using the Green's function method. We clarify the effect of intra-chain and inter-chain exchange interactions on magnetic…

BaMn2As2 is unique among BaT2As2 compounds crystallizing in the body-centered-tetragonal ThCr2Si2 structure, which contain stacked square lattices of 3d transition metal T atoms, since it has an insulating large-moment (3.9 muB/Mn) G-type…

The magnetic structure of the edge sharing cuprate compound Li2CuO2 has been investigated by means of ab initio electronic structure calculations. The first and second neighbor in-chain magnetic interactions are calculated to be -142 K and…

Sr_2Cu_3O_4Cl_2 is an antiferromagnet consisting of weakly coupled CuO planes which comprise two weakly interacting antiferromagnetic subsystems, I and II, which order at respective temperatures T_I \approx 390K and T_{II} \approx 40K.…

The new antiferromagnetic (AF) compound BaCu_2Si_2O_7 is studied by magnetic susceptibility and neutron scattering techniques. The observed behavior is dominated by the presence of loosely coupled S=1/2 chains with the intrachain AF…

We report the magnetic susceptibility and the low-temperature specific heat of a double perovskite compound, Sr2CuTeO6, which is expected as the spin-1/2 square-lattice Heisenberg antiferromagnet with nearest-neighbor J1 and…

The magnetic behaviour of the low-dimensional Vanadium-oxides Sr2V3O9 and Ba2V3O9 was investigated by means of magnetic susceptibility and specific heat measurements. In both compounds, the results can be very well described by an S=1/2…

We report measurements of the specific heat and the thermal conductivity of the model Heisenberg spin-1/2 chain cuprate Sr$_{2}$CuO$_{3}$ at low temperatures. In addition to a nearly isotropic phonon heat transport, we find a quasi…