275 research outputs found
Cytoskeleton organisation during the infection of three brown algal species, Ectocarpus siliculosus, Ectocarpus crouaniorum and Pylaiella littoralis, by the intracellular marine oomycete Eurychasma dicksonii
Funded by ā¢University of Athens ā¢TOTAL Foundation ā¢European Commission ā¢ASSEMBLE. Grant Number: 227788 ā¢MASTS ā¢Scottish Funding Council. Grant Number: HR09011 ā¢UK NERC. Grant Number: NE/J00460X/1Peer reviewedPostprintPostprin
Spin States of Cobalt Ions in the Bulk and on the Surface of LaCoO3 Probed by X-ray Absorption, Emission, and Photoelectron Spectra
We present X-ray photoelectron, Co L2,3 and O K X-ray absorption, as well as Co KĪ²1,3 X-ray emission spectroscopy results of studies of the spin states of trivalent cobalt ions in single-crystal cobaltite LaCoO3. We show that at room temperature, in the bulk of a LaCoO3 single crystal, Co3+ ions are in the low-spin state, while high-spin Co2+, high-spin Co3+, low-spin Co3+ , and probably also intermediate-spin Co3+ ions are localated on the surface
Electronic structure study by means of X-ray spectroscopy and theoretical calculations of the "ferric star" single molecule magnet
The electronic structure of the single molecule magnet system
M[Fe(L)2]3*4CHCl3 (M=Fe,Cr; L=CH3N(CH2CH2O)2) has been studied using X-ray
photoelectron spectroscopy, X-ray absorption spectroscopy, soft X-ray emission
spectroscopy, and density functional calculations. There is good agreement
between theoretical calculations and experimental data. The valence band mainly
consists of three bands between 2 eV and 30 eV. Both theory and experiments
show that the top of the valence band is dominated by the hybridization between
Fe 3d and O 2p bands. From the shape of the Fe 2p spectra it is argued that Fe
in the molecule is most likely in the 2+ charge state. Its neighboring atoms
(O,N) exhibit a magnetic polarisation yielding effective spin S=5/2 per iron
atom, giving a high spin state molecule with a total S=5 effective spin for the
case of M = Fe.Comment: Fig.2 replaced as it will appear in J. Chem. Phy
Electronic and magnetic structure of epitaxial NiO/FeO(001) heterostructures grown on MgO(001) and Nb-doped SrTiO(001)
We study the underlying chemical, electronic and magnetic properties of a
number of magnetite based thin films. The main focus is placed onto
NiO/FeO(001) bilayers grown on MgO(001) and Nb-SrTiO(001)
substrates. We compare the results with those obtained on pure FeO(001)
thin films. It is found that the magnetite layers are oxidized and Fe
dominates at the surfaces due to maghemite (-FeO) formation,
which decreases with increasing magnetite layer thickness. From a layer
thickness of around 20 nm on the cationic distribution is close to that of
stoichiometric FeO. At the interface between NiO and FeO we
find the Ni to be in a divalent valence state, with unambiguous spectral
features in the Ni 2p core level x-ray photoelectron spectra typical for NiO.
The formation of a significant NiFeO interlayer can be excluded by
means of XMCD. Magneto optical Kerr effect measurements reveal significant
higher coercive fields compared to magnetite thin films grown on MgO(001), and
a 45 rotated magnetic easy axis. We discuss the spin magnetic moments
of the magnetite layers and find that the moment increases with increasing thin
film thickness. At low thickness the NiO/FeO films grown on
Nb-SrTiO exhibits a significantly decreased spin magnetic moments. A
thickness of 20 nm or above leads to spin magnetic moments close to that of
bulk magnetite
Spinel ferrite nanocrystals embedded inside ZnO: magnetic, electronic and magneto-transport properties
In this paper we show that spinel ferrite nanocrystals (NiFe2O4, and CoFe2O4)
can be texturally embedded inside a ZnO matrix by ion implantation and
post-annealing. The two kinds of ferrites show different magnetic properties,
e.g. coercivity and magnetization. Anomalous Hall effect and positive
magnetoresistance have been observed. Our study suggests a
ferrimagnet/semiconductor hybrid system for potential applications in
magneto-electronics. This hybrid system can be tuned by selecting different
transition metal ions (from Mn to Zn) to obtain various magnetic and electronic
properties.Comment: 12 pages, 14 figs. accepted for publication at PR
Biogeography pattern of the marine angiosperm Cymodocea nodosa in the eastern Mediterranean Sea related to the quaternary climatic changes
Acknowledgments This research has been co-financed by the European Union (European Social Fund ā ESF) and Greek national funds through the Operational Program "Education and Lifelong Learning" of the National Strategic Reference Framework (NSRF) - Research Funding Program: THALES. The authors would like to thank M. Malandrakis and A. Lolas for their contribution to sampling.Peer reviewedPublisher PD
Diversity and composition of algal epiphytes on the Mediterranean seagrass Cymodocea nodosa : a scale-based study
Acknowledgements This work has been conducted at the Fisheries Research Institute (ELGO DIMITRA) as an undergraduate dissertation of Soultana Tsioli at the University of Patras with supervisors Prof. E. Papastergiadou and Dr. S. Orfanidis. FCK received funding from the UK Natural Environment Research Council (NERC, program Oceans 2025 ā WP 4.5 and grants NE/D521522/1 and NE/J023094/1). Sequencing was conducted at the Molecular Genetics Facility (MGF) of NERC, supported by grant MGF 154.Peer reviewedPostprin
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