In this paper the specific properties of free clusters and the formation of new cluster-assembled materials using the low energy cluster beam deposition (LECBD) technique are discussed. Recent results obtained for free clusters are summarized with special attention to new observed structures. As for the specific structures and properties of cluster-assembled materials, two main aspects are specially emphasized: the memory effect of the free cluster properties leading to the formation of new phases and the effect of the specific nanostructure of the cluster-assembled materials related to the random cluster stacking mechanism characteristic of the LECBD. These effects and the corresponding potential applications are illustrated using some selected examples: new diamond-like carbon films produced by fullerene depositions (memory effect) and grain effect on the magnetic properties of cluster-assembled transition metal films.

The electronic structure of a chiral Yb(III)-based complex is fully determined by taking advantage of experimental magnetic, luminescence, and chiroptical (NIR-ECD and CPL) characterizations in combination with ab-initio wavefunction calculations....

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Single-photon photodetachment of mass-selected W n Ϫ clusters has been studied by photoelectron imaging spectroscopy. Velocity map imaging allows us to measure simultaneously the kinetic-energy spectrum and the angular distribution of photoelectrons. This provides a clear distinction between the two major decay mechanisms: isotropic thermionic emission and anisotropic direct photoemission. A careful study of threshold electrons shows that the thermal distribution cannot be described by a bulklike formula or a simple exponentially decreasing Boltzmann function. On the contrary, our results are in excellent agreement with more refined theoretical models taking into account the spherical symmetry of the cluster. The kinetic-energy distribution of thermal electrons corresponding to thermionic emission is found to vary as p(⑀)ϰ⑀ 1/2 exp(Ϫ⑀/k B T). Our results indicate that a transition toward a bulklike statistical behavior of the internal-energy redistribution occurs in very small systems owing to the high density of states in metal clusters. Moreover, the angular distribution of direct photoelectrons is obtained and the evolution as a function of size is discussed. The asymmetry parameter ␤ of the most intense band observed in direct photoemission for each cluster decreases monotonically with size: the direct photoemission of smaller systems is strongly anisotropic, becoming isotropic as the size of the system increases. This probably indicates the loss of coherence induced by electron-electron collisions occurring in large systems.

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A field‐induced chiral YbIII Single‐Molecule Magnet (SMM) displayed an unprecedented near‐infrared circularly polarized luminescence (NIR‐CPL) in the solid‐state. The bridging bis(1,10‐phenantro[5,6b])tetrathiafulvalene triad (L) allowed an efficient sensitization of the NIR 2F5/2→2F7/2 emission while the NIR‐CPL is associated to the f‐f transitions of the YbIII ion bearing chiral β‐diketonate derived‐camphorate ancillary ligands.

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Mass spectra of Al/v clusters produced by a laser vaporization source have been recorded via standard time-of-flight spectroscopic methods. Regular signal oscillations are observed in the size range /V-200-900 when low-power near-threshold ionization is performed. This striking feature, which is a manifestation of the electronic shell structure of the aluminum clusters, is analyzed with the semiclassical theory of single-particle level density. The oscillation frequency is found to be well explained by the classical star orbit contribution. 03.65.Sq, 36.40.+d Most of the simple metal cluster properties reflect the electronic shell structure of the delocalized valence electrons. Large peaks and steps observed in cluster mass spectra or sudden discontinuities along the cluster size evolution of physical properties, such as the static polarizability or the ionization potential, are in many cases direct manifestations of this shell structure [1]. The underlying theoretical framework relevant to these clusters is similar to the shell theories applying to atoms and nuclei [2]. Except for the differences in the fundamental physical interaction or the potential shape, all these systems are well described in first approximation as a population of N e independent fermions moving in an effective one-particle spherical potential. In the spherical jellium model, worked out using the density-functional formalism [3,4], the discontinuities in the electronic properties arise after the filling of the Kohn-Sham subshells in J) by 2(2/4-1) valence electrons [5][6][7]. Among these filling numbers, which depend on the order of the («,/) levels, the characteristic sizes giving the most pronounced effects (magic numbers) correspond to the filling of successive groupings of subshells. For large sizes this bunching phenomenon is a general trend of systems whose classical motion is multiply periodic [8]. It has been proved by jellium calculations, and the related magic numbers have been observed via oscillations in mass spectra of Na", Cs"0, and Cs rt (S02) clusters [9][10][11][12]. However, as the cluster size increases the level density near the Fermi energy Ep becomes so large that the frontiers between adjacent bunches are blurred and cannot be determined unambiguously. Moreover, owing to the limits of selfconsistent jellium calculations for high structured state densities, to the unavoidable effective width of the levels principally due to the finite temperature of the clusters n(E) -2^(M,^)]exp[-X ? r(M,£ <7[13], and to the different simultaneous scales at which level clustering can occur, a more suitable approach is required.Recently, in a theoretical paper, Nishioka et al. have emphasized the fact that large simple metal clusters constitute the first real system models to exhaustively exemplify the semiclassical theory of single-particle quantum level density [13]. The interpretation of this theory has its foundations in early work by Gutzwiller [14]. It has been developed by Balian and Bloch in the case of empty...