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MATERIALS SCIENCE BEAMLINE, ELETTRA TRIESTE - NEW INSTRUMENT FOR SURFACE SCIENCE
Vašina, R. ; Doležel, P. ; Vondráček, Martin ; Cháb, Vladimír ; Prince, K. C. ; Ressel, B.
The Materials Science Beamline is attached to a bending magnet at synchrotron Elettra Trieste, Italy. The tuning range is from 35 to 800 eV with calculated spectral resolving power E/delta E better than 4000 in the whole range. The optical elements consist of a toroidal prefocusing mirror, polarization aperture, entrance slit, plane pre-mirror, single plane grating (blazed), spherical mirror, exit slit and toroidal refocusing mirror. The plane grating is operated in the fixed focus mode with Cff = 2.4. Energy scanning is performed by rotation of the plane grating and simultaneous translation and rotation of the plane pre-mirror. In the first tests, a resolving power of at least 4000 has been achieved at energies of 400 eV. The calculated photon flux at the sample is compared with measured values. Various experimental chambers depending on experiments can be attached to the beamline (LEEM, ESCA).
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Ab initio simulation of a tensile test in iron
Friák, Martin ; Šob, Mojmír ; Vitek, V.
A tensile test in ferromagnetic and nonmagnetic iron is simulated by ab initio electronic structure calculations using all-electron full potential linearized augmented plane wave method (FLAPW) within generalized gradient approximation (GGA). The theoretical tensile strength of ferromagnetic iron for [001] loading is determined and compared with that of other materials. The magnetic behavior of iron under tensile loading is studied in detail and compared with results for triaxial loading.
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Ab initio calculations of theoretical strength and phase stability in copper
Černý, M. ; Šob, Mojmír ; Šandera, P.
Simulation of tensile test of copper cryslat along <001> is performed using ab initio full-potential linear augmented plane waves (FLAPW) method. Both the local density approximation (LDA) and generalized gradient approximation (GGA) are used to evaluate exchange-correlation contribution to the total energy. Equilibrium lattice parameter and Young modulus are computed ro assess reliability of our results by comparing them with experiment. Stability conditions for uniaxially loaded system are presented and analyzed. Finally, the ideal strength (IS) is calculated.
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