The Highly Frustrated 5d Double Perovskite Doppelgängers, SrLaMgReO and SrLaLiOsO. A Comparison including Isostructural LaLiReO.

The synthesis and characterization of the double perovskite SrLaLiOsO is presented. It is isostructural (2/) and isoelectronic (5d) with SrLaMgReO, which has been reported previously. The cell volumes are the same to within 1.

Valence tautomerism in a [2 × 2] Co grid complex containing a ditopic arylazo ligand.

We describe the structural and magnetic properties of a tetranuclear [2 × 2] Co4 grid complex containing a ditopic arylazo ligand. At low temperatures and in solution the complex is comprised of Co3+ and singly reduced trianion-radical ligands. In the solid state we demonstrate the presence of valence tautomerization via variable temperature magnetic susceptibility experiments and powder-pattern EPR spectroscopy.

Understanding the Interplay of Vacancy, Cation, and Charge Ordering in the Tunable ScVO Defect Fluorite System.

We report the synthesis, structure, and redox behavior of the cation-ordered tetragonal ScVO defect fluorite superstructure previously thought to be the oxygen precise ABO phase. Four synthesis routes in oxidative, reductive, and inert atmospheres are demonstrated. and powder X-ray and neutron diffraction analyses reveal vanadium disproportionation reactions.

Structure and Magnetic Properties of KRuO.

The crystal structure of KRuO is refined at both 280 and 3.5 K from neutron powder data, and magnetic properties are reported for the first time. The scheelite structure, I4/a, is confirmed at both temperatures.

Order/Disorder and in Situ Oxide Defect Control in the Bixbyite Phase YPrO3+δ (0 ≤ δ < 0.5).

The YPrO3+δ system is a nearly ideal model system for the investigation of oxide defect creation and annihilation in oxide ion conductor related phases with potential applications as solid state electrolytes in solid oxide fuel cells. The formation, structure, high temperature reactivity, and magnetic susceptibility of phase pure YPrO3+δ (0 ≤ δ ≤ 0.46) are reported.

Rhodium(ii) dimers without metal-metal bonds.

Oxidation of ((Me)BDI)Rh(cyclooctene) ((Me)BDI = [2,6-Me(2)C(6)H(3)NCMe](2)CH) with Br(2) or I(2) produces paramagnetic halide-bridged Rh(II) dimers [((Me)BDI)Rh](2)(μ-X)(2) without a direct Rh-Rh bond. Steric factors are proposed to play a key role in preventing the formation of Rh-Rh bonded alternative structures.

Observation of magnetic polarons in the magnetoresistive pyrochlore Lu2V2O7.

Materials that exhibit colossal magnetoresistance (CMR) have attracted much attention due to their potential technological applications. One particularly interesting model for the magnetoresistance of low-carrier-density ferromagnets involves mediation by magnetic polarons (MP)-electrons localized in nanoscale ferromagnetic 'droplets' by their exchange interaction. However, MP have not previously been directly detected and their size has been difficult to determine from macroscopic measurements.