The spin and orbit contributions to the magnetic moments of isolated clusters

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We plan to pursue an in depth investigation of the spin and orbit contributions to the total magnetic moments of free transition metal clusters while tuning cluster size, cluster composition, adsorbate coverage, cluster temperature and external magnetic field. We propose to obtain the spin and orbit contributions through application of X-ray induced magnetic circular dichroism (XMCD) to the gas phase metal clusters of selected sizes when isolated within a Penning type ion trap. This novel experimental scheme shall allow for the determination of total magnetic moments as arising through spin and orbit contributions. Temperature tuning and B-field tuning shall allow for the recording of magnetization curves. This shall be enabled through application of tunable circularly polarized X-ray synchrotron radiation to isolated gas phase transition metal clusters that have been size selected and stored in an Fourier-Transform-lon-Cyclotron-Resonance (FT-ICR) ion trap under ultra high vacuum. Cryogenic control of cluster temperature throughout the course of the actual experiment turns out to become crucial. As is standard in large scale concerted experiments we choose to coin an acronym for unambiguous identification of our effort: Generalized Abstraction of Magnetic moments at BESSY by Ion Trapping GAMBIT The new GAMBIT setup is scheduled for stationary installation in Berlin at the BESSY synchrotron user beam line BL52-PGM which interfaces to the undulator UE 52. It shall be operated jointly by the three groups of this proposal and will become available to further users who qualify through application and approval in the course of standard procedures.