F. Baudelet - Academia.edu (original) (raw)
Papers by F. Baudelet
Physical review. B, Condensed matter, 1994
Physical Review B, 2010
... REVIEW B 82, 140412Í RÍ Í 2010Í Absence of abrupt pressure-induced magnetic transitions in ma... more ... REVIEW B 82, 140412Í RÍ Í 2010Í Absence of abrupt pressure-induced magnetic transitions in magnetite François Baudelet,1,2 Sakura Pascarelli,3 ... 16 E. Dartyge, F. Baudelet, C. Brouder, A. Fontaine, C. Giorgetti, JP Kappler, G. Krill, MF Lopez, and S. Pizzini, Physica B 208 ...
Physica B: Condensed Matter, 1995
We report X-ray magnetic circular dichroism at the Kedge of Cr, Mn, Ni and N, in molecule-based m... more We report X-ray magnetic circular dichroism at the Kedge of Cr, Mn, Ni and N, in molecule-based magnets of the Prussian Blue family. The effect (0.5 %) is visible at the metallic K edge in the white line. An interpretation of the XMCD structure is proposed and a multiplet calculation at the nickel edge reported.
Physica B: Condensed Matter, 1995
To explain the low-energy features of magnetic circular X-ray dichroism (MCXD) at L edges of rare... more To explain the low-energy features of magnetic circular X-ray dichroism (MCXD) at L edges of rare earth compounds, quadrupolar electric transitions (E2) from 2p to 4f levels have been invoked. Such transitions should be distinguished from dipolar electric (El) ones by looking at the different behaviour of the E1 and E2 MCXD cross sections as a function of the temperature and the angle between the quantization axis and the photon wave vector. However, convincing experimental proof of such transitions has not yet been given. A good candidate for these key tests is Yb, where the E2 transitions are allowed at the L3 edge and forbidden at the L2 edge. In YbFe2, we observe an important change in the shape of the spectrum with temperature at the L 3 edge of Yb.
Journal of Physics: Conference Series, 2009
In Earth and Materials sciences, iron is the most important transition element. Glass and melt pr... more In Earth and Materials sciences, iron is the most important transition element. Glass and melt properties are strongly affected by iron content and redox state , with the consequence that some properties (i.e. viscosity, heat capacity, crystallization…) depend not only on the amounts of Fe 2+ and Fe 3+ , but also on the coordination state of these ions. In this work we investigate iron redox reactions through XANES experiments at the K-edge of iron. Using a high-temperature heating device, pre-edge of XANES spectra exhibits definite advantages to make in-situ measurements and to determine the evolution of redox state with time, temperature and composition of synthetic silicate melts. In this study, new kinetics measurements are presented for a basalt melt from the 31,000-BC eruption of the Puy de Lemptegy Volcano in France. These measurements have been made between 773 K and at superliquidus temperatures up to 1923 K.
Journal of Magnetism and Magnetic Materials, 1991
X-ray scattering and EXAFS are used to probe epitaxial strain in Co-Au superlattices grown by mol... more X-ray scattering and EXAFS are used to probe epitaxial strain in Co-Au superlattices grown by molecular beam epitaxy. We observe a thickness-dependent strain in ultrathin cobalt layers and find that tensile strains near misfit dislocations may be larger than in the more coherent interior of the Co layers. A strong enhancement of the magnetic absorption spectrum is observed in the superlattice samples.
Journal of Magnetism and Magnetic Materials, 1992
Magnetic X-ray dichroism experiments, using circularly polarized X-ray photons (CMXD), have been ... more Magnetic X-ray dichroism experiments, using circularly polarized X-ray photons (CMXD), have been performed on several rare-earth(RE)-Fe intermetallics both at the Ln.lU absorption edges of the rare earth and at the K edge of iron. We show in this communication how such experiments can yield direct information about the local magnetic properties of RE and Fe atoms in these intermetallic compounds. We demonstrate that CMXD experiments are able both to reveal the existence of an ordered magnetic moment on the various sites independently and the nature of coupling between the RE and the Fe magnetic moments.
Journal of The Electrochemical Society, 2010
... and data simulation were very successful in allowing a precise analysis of chemical bonds dur... more ... and data simulation were very successful in allowing a precise analysis of chemical bonds during electrochemical lithium insertion/extraction. ... Triphylite , a material of choice to be used as a positive electrode in the next generation of Li-ion batteries particularly suited for ...
Journal of Alloys and Compounds, 2004
Applied Physics Letters, 2002
Dense powder of nanocrystalline ZnO has been recovered at ambient conditions in the metastable cu... more Dense powder of nanocrystalline ZnO has been recovered at ambient conditions in the metastable cubic structure after a heat treatment at high pressure ͑15 GPa and 550 K͒. Combined x-ray diffraction ͑XRD͒ and x-ray absorption spectroscopy ͑XAS͒ experiments have been performed to probe both long-range order and local crystallographic structure of the recovered sample. Within uncertainty of these techniques ͑about 5%͒, all the crystallites are found to adopt the NaCl structure. From the analysis of XRD and XAS spectra, the cell volume per chemical formula unit is found to be 19.57͑1͒ and 19.60(3) Å 3 , respectively, in very good agreement with the zero-pressure extrapolation of previously published high-pressure data.
Physical review. B, Condensed matter, 1994
Physical Review B, 2010
... REVIEW B 82, 140412Í RÍ Í 2010Í Absence of abrupt pressure-induced magnetic transitions in ma... more ... REVIEW B 82, 140412Í RÍ Í 2010Í Absence of abrupt pressure-induced magnetic transitions in magnetite François Baudelet,1,2 Sakura Pascarelli,3 ... 16 E. Dartyge, F. Baudelet, C. Brouder, A. Fontaine, C. Giorgetti, JP Kappler, G. Krill, MF Lopez, and S. Pizzini, Physica B 208 ...
Physica B: Condensed Matter, 1995
We report X-ray magnetic circular dichroism at the Kedge of Cr, Mn, Ni and N, in molecule-based m... more We report X-ray magnetic circular dichroism at the Kedge of Cr, Mn, Ni and N, in molecule-based magnets of the Prussian Blue family. The effect (0.5 %) is visible at the metallic K edge in the white line. An interpretation of the XMCD structure is proposed and a multiplet calculation at the nickel edge reported.
Physica B: Condensed Matter, 1995
To explain the low-energy features of magnetic circular X-ray dichroism (MCXD) at L edges of rare... more To explain the low-energy features of magnetic circular X-ray dichroism (MCXD) at L edges of rare earth compounds, quadrupolar electric transitions (E2) from 2p to 4f levels have been invoked. Such transitions should be distinguished from dipolar electric (El) ones by looking at the different behaviour of the E1 and E2 MCXD cross sections as a function of the temperature and the angle between the quantization axis and the photon wave vector. However, convincing experimental proof of such transitions has not yet been given. A good candidate for these key tests is Yb, where the E2 transitions are allowed at the L3 edge and forbidden at the L2 edge. In YbFe2, we observe an important change in the shape of the spectrum with temperature at the L 3 edge of Yb.
Journal of Physics: Conference Series, 2009
In Earth and Materials sciences, iron is the most important transition element. Glass and melt pr... more In Earth and Materials sciences, iron is the most important transition element. Glass and melt properties are strongly affected by iron content and redox state , with the consequence that some properties (i.e. viscosity, heat capacity, crystallization…) depend not only on the amounts of Fe 2+ and Fe 3+ , but also on the coordination state of these ions. In this work we investigate iron redox reactions through XANES experiments at the K-edge of iron. Using a high-temperature heating device, pre-edge of XANES spectra exhibits definite advantages to make in-situ measurements and to determine the evolution of redox state with time, temperature and composition of synthetic silicate melts. In this study, new kinetics measurements are presented for a basalt melt from the 31,000-BC eruption of the Puy de Lemptegy Volcano in France. These measurements have been made between 773 K and at superliquidus temperatures up to 1923 K.
Journal of Magnetism and Magnetic Materials, 1991
X-ray scattering and EXAFS are used to probe epitaxial strain in Co-Au superlattices grown by mol... more X-ray scattering and EXAFS are used to probe epitaxial strain in Co-Au superlattices grown by molecular beam epitaxy. We observe a thickness-dependent strain in ultrathin cobalt layers and find that tensile strains near misfit dislocations may be larger than in the more coherent interior of the Co layers. A strong enhancement of the magnetic absorption spectrum is observed in the superlattice samples.
Journal of Magnetism and Magnetic Materials, 1992
Magnetic X-ray dichroism experiments, using circularly polarized X-ray photons (CMXD), have been ... more Magnetic X-ray dichroism experiments, using circularly polarized X-ray photons (CMXD), have been performed on several rare-earth(RE)-Fe intermetallics both at the Ln.lU absorption edges of the rare earth and at the K edge of iron. We show in this communication how such experiments can yield direct information about the local magnetic properties of RE and Fe atoms in these intermetallic compounds. We demonstrate that CMXD experiments are able both to reveal the existence of an ordered magnetic moment on the various sites independently and the nature of coupling between the RE and the Fe magnetic moments.
Journal of The Electrochemical Society, 2010
... and data simulation were very successful in allowing a precise analysis of chemical bonds dur... more ... and data simulation were very successful in allowing a precise analysis of chemical bonds during electrochemical lithium insertion/extraction. ... Triphylite , a material of choice to be used as a positive electrode in the next generation of Li-ion batteries particularly suited for ...
Journal of Alloys and Compounds, 2004
Applied Physics Letters, 2002
Dense powder of nanocrystalline ZnO has been recovered at ambient conditions in the metastable cu... more Dense powder of nanocrystalline ZnO has been recovered at ambient conditions in the metastable cubic structure after a heat treatment at high pressure ͑15 GPa and 550 K͒. Combined x-ray diffraction ͑XRD͒ and x-ray absorption spectroscopy ͑XAS͒ experiments have been performed to probe both long-range order and local crystallographic structure of the recovered sample. Within uncertainty of these techniques ͑about 5%͒, all the crystallites are found to adopt the NaCl structure. From the analysis of XRD and XAS spectra, the cell volume per chemical formula unit is found to be 19.57͑1͒ and 19.60(3) Å 3 , respectively, in very good agreement with the zero-pressure extrapolation of previously published high-pressure data.