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The \(\bar{\text{ P }}\)ANDA experiment at FAIR in Darmstadt will perform a fixed target experiment by using a cooled beam of antiprotons in the momentum range between 1.5 to 15 GeV/c to study open questions in hadron physics. The core program comprises charmonium spectroscopy with precision measurement of mass, width and decay branches, investigation of possible exotic states, search for modifications of charmed hadrons in nuclear matter and \(\gamma \)-ray spectroscopy of hypernuclei.

Thin amorphous films of ZrB3 grown on Si(111) substrates by chemical-vapor deposition are, upon annealing at 960 °C, transformed to films composed of nanocrystallites (6–10 nm extent) with a nominal composition of Zr0.9Si0.3B3. The independent elastic constants of the layers are determined from the dispersion of the surface and pseudo-Sezawa acoustic excitations and reveal large enhancements in the C11 and C44 constants accompanying the conversion of ZrB3 to the nanocrystalline phase. Since the transverse sound velocities of the binary and Zr0.9Si0.3B3 are in near resonance with the sound velocity of Si (VTSi=4.8 km/s), only the Rayleigh surface wave is localized to the film while all higher-order acoustic modes are evanescent. Despite the strong decay channels, high-lying excitations with velocities as large as 25 km/s (≫VTSi) are observed in Brillouin light scattering. Insight into these acoustic properties is provided by evaluating the elastodynamic Green’s functions and associated acoustic-mode densities.

The wave vector dependence of Rayleigh and higher order Sezawa elastic waves in single crystalline epitaxial face-centered-cubic (fcc) Co layers are measured by Brillouin light scattering at room temperature. The dispersion of the mode velocities allows the independent elastic constants to be determined for this cubic phase of cobalt. These results compare very favorably to previous determinations of the elastic constants measured above 700 K from the high-temperature fcc phase of pure Co. Deviations from theoretical estimates are discussed.

We report experimental as well as theoretical evidence for the occurrence of a high-frequency acoustic excitation, identified as a longitudinal guided mode, in elastically hard films supported on a soft substrate. While existence criteria related to the transverse and longitudinal sound velocities in the film and substrate argue for strong decay channels into the substrate, the excitation is evident as a clear peak in the Brillouin light scattering spectra. A Green's function formalism accounts for the existence of this excitation and provides insight into its properties as illustrated for diamond-like-carbon layers deposited on silicon.

In this article, we present an experimental procedure to synthesize highly crystalline FeCO3 by hydrothermal decomposition of Fe(III)‐EDTA complex, starting from Ferric Ammonium Sulfate and Na4EDTA main precursors in urea presence. The structure, morphology and composition of the powders were obtained using X‐ray powder diffraction and scanning electron microscopy. The peaks were founded, indicate that the synthesized products autoclaved 22 h at 250 °C are pure FeCO3, which was well proved experimentally from EDAX further investigated. The size with appreciatively 100 μm was evaluated by SEM images. Magnetic characterization confirmed the magnetic characteristics of FeCO3. This procedure allowed the FeCO3 microparticles formation with good and stabile crystallographic characteristics.

We report on the localization of acoustic waves in GaN-AlN heterolayers deposited on Si that lead to the observation, by Brillouin light scattering, of distinctive guided excitations associated with the hexagonal $(2H)$ GaN epilayers. These elastic modes include the longitudinal guided resonance (LGR) propagating parallel to the film surface and a shear horizontal resonance (SHR) polarized in the plane of the surface. The observation in light scattering of guided excitations arise from the strong elasto-optic properties of the GaN thin films as well as the presence of AlN that acts as a barrier by reducing energy leakage to the substrate. Calculations of the mode density and displacements disclose characteristics of the LGR and SHR and account for their localization and polarization features. Several of the principal elastic constants of the GaN layer are determined from the data that also reveal the bulk acoustic phonons and the Rayleigh surface mode.

We report on a new high frequency excitation, identified as a longitudinal guided mode, supported in a hard isotropic film deposited on a substrate. The observation of this mode allows for a direct determination of the C11 elastic constant of the film. The remaining constant, C44, was determined through a least square fit to the dispersion of the pseudo surface wave. Properties of the observed excitations were investigated by evaluating their mode density and polarization characteristics.

Diamondlike carbon (DLC) thin films have been widely used as hard coatings in a variety of applications where increased wear resistance and hardness are required. Vacuum arc DLC films are among the hardest, with measured hardness values of up to 68 GPa. In our deposition process a repetitively pulsed bias voltage is applied to the substrate, which controls the energy of the incoming C ions. DLC chemical and mechanical properties are strongly affected by the energy of the depositing ions. In this paper, we relate the mechanical properties of these films to the deposition parameters, and describe our initial Brillouin scattering measurements of the elastic constants of monolithic DLC films. Evidence for bulk longitudinal and surface Rayleigh excitation in films with thickness of 50 and 500 nm has been observed. Since the DLC films are amorphous, they are modeled as isotropic solids and the elastic constants CII and C44 are derived.

Coupling mechanisms between ${\mathrm{Co}}_{0.75}{\mathrm{Fe}}_{0.25}$ films separated by Mn layers are investigated using Brillouin light scattering from thermal spin waves. Trilayers of CoFe/Mn/CoFe, grown by molecular-beam epitaxy, were studied with Mn thicknesses between 6 and 30 \AA{}. Spin-wave excitations corresponding to acoustic and optic modes in double layer magnetic structures were observed, and allowed a determination of a strong magnetic coupling between the CoFe films. Spin-wave frequencies were examined as functions of applied field, Mn film thickness, and temperature. A microscopic model is used to examine magnetic order in a ferromagnet/antiferromagnet/ferromagnet structure. Discrepancies between the data and predictions of the microscopic model provide evidence for a twist in the FeCo spins that extends into the ferromagnet layer.