Chris D. Ling

Does local disorder occur in the pyrochlore zirconates

The zirconates Ln(2)Zr(2)O(7) (Ln = lanthanoid) have been studied using a combination of Zr L-edge X-ray absorption near edge structure (XANES) and synchrotron X-ray and neutron powder diffraction methods. These studies demonstrate that as the size of the lanthanoid cation decreases, the local structure evolves smoothly from the ideal pyrochlore toward the defect fluorite rather than undergoing an abrupt transformation. The Zr L-edge spectrum is found to be extremely sensitive to changes in the local coordination environment and demonstrates an increase in local disorder across the pyrochlore oxides. The sensitivity of the XANES measurements enables us to identify the progressive nature of the transition that could not be detected using bulk diffraction techniques.

Magnetic structures of NaFePO4 maricite and triphylite polymorphs for sodium-ion batteries.

The magnetic structure and properties of polycrystalline NaFePO4 polymorphs, maricite and triphylite, both derived from the olivine structure type, have been investigated using magnetic susceptibility, heat capacity, and low-temperature neutron powder diffraction. These NaFePO4 polymorphs assume orthorhombic frameworks (space group No. 62, Pnma), built from FeO6 octahedral and PO4 tetrahedral units having corner-sharing and edge-sharing arrangements. Both polymorphs demonstrate antiferromagnetic ordering below 13 K for maricite and 50 K for triphylite. The magnetic structure and properties are discussed considering super- and supersuperexchange interactions in comparison to those of triphylite-LiFePO4.

Glass transition in the polaron dynamics of colossal magnetoresistive manganites.

Neutron scattering measurements on a bilayer manganite near optimal doping show that the short-range polaron correlations are completely dynamic at high T, but then freeze upon cooling to a temperature T(*) approximately equal 310 K. This glass transition suggests that the paramagnetic/insulating state arises from an inherent orbital frustration that inhibits the formation of a long-range orbital- and charge-ordered state. Upon further cooling into the ferromagnetic-metallic state (T(C) = 114 K), where the polarons melt, the diffuse scattering quickly develops into a propagating, transverse optic phonon.

Inhomogeneous magnetism in La-dopedCaMnO3. II. Nanometric-scale spin clusters and long-range spin canting

Neutron measurements on

Magnetic structure and properties of the Na2CoP2O7 pyrophosphate cathode for sodium-ion batteries: a supersuperexchange-driven non-collinear antiferromagnet.

{\mathrm{Ca}}_{1\ensuremath{-}x}{\mathrm{La}}_{x}{\mathrm{MnO}}_{3}

Ionothermal Synthesis of High-Voltage Alluaudite Na2+2xFe2-x(SO4)(3) Sodium Insertion Compound: Structural, Electronic, and Magnetic Insights

(0.00l~xl~0.20)

Structural and magnetic behavior of a quasi-1D antiferromagnetic chain compound Cu(NCS)2(pyz)

reveal the development of magnetic droplets showing a liquidlike intercluster spatial distribution. The average size of the droplets is

Neutron diffraction study of the Li-ion battery cathode Li2FeP2O7.

\ensuremath{\sim}10\mathrm{\AA{}},

Structure of nanoscale polaron correlations in La 1.2 Sr 1.8 Mn 2 O 7

the concentration of which in the G-AFM matrix being proportional to x (one cluster per