Y. Skourski

Magnetization and specific heat of TbFe3"BO3…4: Experiment and crystal-field calculations

ions inthe trigonal crystal field. Our experimental data are analyzedin the context of the unified approach which is based onmean-field approximation and crystal-field calculations. Thespin-flop transition is apparently accompanied by magneto-elastic effects. Magnetoelectric effects might therefore be as-sociated with the spin-flop transition, leading TbFe

Saturation Field of Frustrated Chain Cuprates: Broad Regions of Predominant Interchain Coupling

A thermodynamic method to extract the interchain coupling (IC) of spatially anisotropic 2D or 3D spin-1/2 systems from their empirical saturation field H(s) (T=0) is proposed. Using modern theoretical methods we study how H(s) is affected by an antiferromagnetic (AFM) IC between frustrated chains described in the J(1)-J(2)-spin model with ferromagnetic 1st and AFM 2nd neighbor in-chain exchange. A complex 3D-phase diagram has been found. For Li(2)CuO(2) and Ca(2)Y(2)Cu(5)O(10), we show that H(s) is solely determined by the IC and predict H(s)≈61 T for the latter. With H(s)≈55 T from magnetization data one reads out a weak IC for Li(2)CuO(2) close to that obtained from inelastic neutron scattering.

CaCuMn6O12 vs. CaCu2Mn5O12: A comparative study

The ferrimagnetic compounds Ca(CuxMn3−x)Mn4O12 of the double distorted perovskites AC3B4O12 family exhibit a rapid increase of the ferromagnetic component in magnetization at partial substitution of square coordinated (Mn3+)C for (Cu2+)C. In the transport properties, this is seen as a change of the semiconducting type of resistivity for the metallic one. The evolution of magnetic properties of Ca(CuxMn3−x)Mn4O12 is driven by strong antiferromagnetic exchange interaction of (Cu2+)C with (Mn3+/Mn4+)B coordinated octahedra. The competing interactions of (Mn3+)C with (Mn3+/Mn4+)B lead to the formation of noncollinear magnetic structures that can be aligned by magnetic fields.