Local and long-range atomic/magnetic structure of non-stoichiometric spinel iron oxide nanocrystallites.

Spinel iron oxide nanoparticles of different mean sizes in the range 10-25 nm have been prepared by surfactant-free up-scalable near- and super-critical hydro-thermal synthesis pathways and characterized using a wide range of advanced structural characterization methods to provide a highly detailed structural description. The atomic structure is examined by combined Rietveld analysis of synchrotron powder X-ray diffraction (PXRD) data and time-of-flight neutron powder-diffraction (NPD) data. The local atomic ordering is further analysed by pair distribution function (PDF) analysis of both X-ray and neutron total-scattering data.

Impact of magnetization and hyperfine field distribution on high magnetoelectric coupling strength in BaTiO-BiFeO multilayers.

Correlations were established between the hyperfine field distribution around the Fe atoms, the multiferroic properties, and the high magnetoelectric coefficient in BaTiO-BiFeO multilayer stacks with variable BiFeO single layer thickness, down to 5 nm. Of key importance in this study was the deposition of Fe - enriched BiFeO, which enhances the sensitivity of conversion electron Mössbauer spectroscopy by orders of magnitude. The magnetoelectric coefficient α reaches a maximum of 60.

X-Ray Diffraction and Mössbauer Spectroscopy Studies of Pressure-Induced Phase Transitions in a Mixed-Valence Trinuclear Iron Complex.

The mixed-valence complex Fe3 O(cyanoacetate)6 (H2 O)3 (1) has been studied by single-crystal X-ray diffraction analysis at pressures up to 5.3(1) GPa and by (synchrotron) Mössbauer spectroscopy at pressures up to 8(1) GPa. Crystal structure refinements were possible up to 4.

Correlation between alkaline earth diffusion and fragility of silicate glasses.

We have studied the correlation between liquid fragility and the inward diffusion (from surface toward interior) of alkaline earth ions in the SiO(2)-Na(2)O-Fe(2)O(3)-RO (R = Mg, Ca, Sr, Ba) glass series. The inward diffusion is caused by reduction of Fe(3+) to Fe(2+) under a flow of H(2)/N(2) (1/99 v/v) gas at temperatures around the glass transition temperature (T(g)). The consequence of such diffusion is the formation of a silica-rich nanolayer.

Indication of drier periods on Mars from the chemistry and mineralogy of atmospheric dust.

The ubiquitous atmospheric dust on Mars is well mixed by periodic global dust storms, and such dust carries information about the environment in which it once formed and hence about the history of water on Mars. The Mars Exploration Rovers have permanent magnets to collect atmospheric dust for investigation by instruments on the rovers. Here we report results from Mössbauer spectroscopy and X-ray fluorescence of dust particles captured from the martian atmosphere by the magnets.