Portable Device for Potentiometric Determination of Antioxidant Capacity.

For the first time, a prototype of a portable device for the potentiometric determination of antioxidant capacity based on a new measurement principle is proposed. A feature of the approach is the use of an electrochemical microcell with separated spaces and two identical electrodes with immobilized reagents. An antioxidant solution is introduced into one half-cell, and the antioxidants interact with the reagents.

New Nabokoite-like Phases ACu TeO (SO ) Cl (A=Na, K, Rb, Cs) with Decorated and Distorted Square Kagome Lattices.

A new family of compounds ACu TeO (SO ) Cl (A=Na, K, Rb, Cs) isostructural to mineral Nabokoite (K species) was synthesized by solid state and gas transport reactions in sealed ampoules and characterized in measurements of magnetization and specific heat in a wide temperature range. These complex compounds are of the utmost interest as a testing playground to study the properties of quasi-two-dimensional magnets with a square kagome lattice geometry. A quantum ground state of such a corner-sharing network is a spin liquid.

Quasi-One-Dimensional Linarite-Type PbCu(SeO)(OH) with Competing Nearest-Neighbor and Next-Nearest-Neighbor Intrachain Exchange Interactions.

PbCu(SeO)(OH), the selenate sibling of the mineral linarite, was synthesized hydrothermally, investigated in measurements of magnetization , specific heat and dielectric permittivity , and analyzed within density functional theory formalism. This quasi-one-dimensional compound evidences formation of a short-range correlation regime at ~ 8 K and experiences a long-range magnetic order at = 4.3 K.

AMnXO Family (A = Li, Na, Ag; X = Si, Ge): Structural and Magnetic Properties.

Four new manganese germanates and silicates, AMnGeO (A = Li, Na) and AMnSiO (A = Na, Ag), were prepared, and their crystal structures were determined using the X-ray Rietveld method. All of them contain all components in tetrahedral coordination. LiMnGeO is orthorhombic (Pmn2) layered, isostructural with LiCdGeO, and the three other compounds are monoclinic (Pn) cristobalite-related frameworks.