Activities of FexO in Na2O-Al2O3-SiO2-FexO Homogeneous Liquid Slags at 1673 K

Electrochemical measurements of the solid-oxide galvanic cell of the type Mo/Mo + MoO[2]/ZrO[2] (MgO)/Fe + {Na[2]O-Al[2]O[3]-SiO[2]-FexO} slag/Ag/Fe were conducted at 1673 K in order to obtain the activities of FexO in Na[2]O-Al[2]O[3]-SiO[2]-FexO system. The iso-activity curves for FexO at 1673 K were determined for Na[2]O-(Al[2]O[3] + SiO[2])-FexO pseudo-ternary slags with an Al[2]O[3]/SiO[2] molar ratio of 33/67

Field-induced incommensurate phase in the strong-rung spin ladder with ferromagnetic legs

We report magnetization, specific heat, and NMR measurements of 3-Br-4-F-V [=3-(3-bromo-4-fluorophenyl)-1,5-diphenylverdazyl], a strong-rung S=1/2 Heisenberg spin ladder with ferromagnetic leg interactions. We explain the magnetic and thermodynamic properties based on the strong-rung regime. Furthermore, we find a field-induced successive phase transition in the specific heat and the nuclear spin-lattice relaxation rate 1/T1. 19F-NMR spectra for higher- and lower-temperature phases indicate partial magnetic order and incommensurate long-range order, respectively, evidencing the presence of frustration due to weak interladder couplings.Comment: 12 pages, 3 figure

Local spin and charge properties of beta-Ag0.33V2O5 studied by 51V NMR

Local spin and charge properties were studied on beta-Ag0.33V2O5, a pressure-induced superconductor, at ambient pressure using 51V-NMR and zero-field-resonance (ZFR) techniques. Three inequivalent Vi sites (i=1, 2, and 3) were identified from 51V-NMR spectra and the principal axes of the electric-field-gradient (EFG) tensor were determined in a metallic phase and the following charge-ordering phase. We found from the EFG analysis that the V1 sites are in a similar local environment to the V3 sites. This was also observed in ZFR spectra as pairs of signals closely located with each other. These results are well explained by a charge-sharing model where a 3d1 electron is shared within a rung in both V1-V3 and V2-V2 two-leg ladders.Comment: 12pages, 16figure

Electronic structure and exchange interactions of the ladder vanadates CaV2O5 and MgV2O5

We have performed ab-initio calculations of the electronic structure and exchange couplings in the layered vanadates CaV2O5 and MgV2O5. Based on our results we provide a possible explanation of the unusual magnetic properties of these materials, in particular the large difference in the spin gap between CaV2O5 and MgV2O5