The objective of the TEMPO project is the creation of a beamline and of an experimental station adapted to the dynamic studies of the electronic and magnetic properties of materials. The project gathers various spectroscopic studies around its specificity, i.e. taking into account the temporal variable. This regards more specifically:
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the determination of the kinetics of chemical reactions at interface and surface by rapid photo-emission in the millisecond range. The high flux coupled to the high energy resolution of the electron energy analyser and of the beamline will allow the user to study the evolution of the chemical environment (surface coordination, chemical bonding with different elements) of selected chemical atoms at the surface using spectroscopic signatures in the electronic states. Physisorption kinetics, chemisorption or dissociation of molecules on a substrate, interface formation and interdiffusion. The understanding of these processes is the key point to build new magnetic materials or to control chemical reactivity and catalytic properties.
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the dynamics of magnetisation reversal in nanostructures, using the temporal characteristics of Soleil at the scale of dozens of picoseconds , a problem of major significance for the magnetic storage of information at ultra-high density. These experiments will be performed using different techniques with different probing depths : X-ray magnetic circular dichroism, Magnetic dichroism in photoemission, and secondary electrons spin polarisation.
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carrying out pump-probe experiments with two photons (laser + synchrotron radiation) for the study of excited states using synchrotron impulses in the temporal range of a picosecond.
The TEMPO beamline results from the transfer of the SB7 beamline [1] of SuperACO onto an insertion device source of Soleil. It covers the photon energy range between 50 eV and 1500 eV. This energy range is particularly well suited for magnetic materials studies and for chemistry applications. On the one hand, UPS (valence band) photoemission is feasible at h n =50 eV. On the other hand, the whole range of K edges (C, O, N, F 1s) of organic molecules, the 4 th period transition metal L (2p) edges of transition metals (with applications to metal-organic molecules and metal surfaces), and M edges of rare earths is covered. With respect to the preceding installations at LURE, the SOLEIL beamlines will provide a general improvement in terms of flux, light polarisation flexibility and time resolution.
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