Comparative analysis of the microstructure and mechanical properties of an Al-Cu-Mg-Ag alloy peak-aged at relatively low and high temperatures

The aim of the present work is to characterize the precipitate microstructure in relationship with the peak mechanical properties of an Al-Cu-Mg-Ag alloy reached after aging at relatively low (150 °C) and high (190 °C) temperature

Structural phases driven by oxygen vacancies at the La0.7Sr0.3MnO3/SrTiO3 hetero-interface

An oxygen vacancy driven structural response at the epitaxial interface between La0.7Sr0.3MnO3 films and SrTiO3 substrates is reported. A combined scanning transmission electron microscopy and electron energy loss spectroscopy study reveal the presence of an elongated out-of-plane lattice parameter, coupled to oxygen vacancies and reduced manganese oxidation state at the La0.7Sr0.3MnO3 side of the interface. Density functional theory calculations support that the measured interface structure is a disordered oxygen deficient brownmillerite structure. The effect of oxygen vacancy mobility is assessed, revealing an ordering of the vacancies with time

Quantitative analysis of {100}Al plate/lath- and <100>Al rod-shaped precipitates in an aged Al-Cu-Mg-Si alloy using TEM

Precipitate parameters, such as length, diameter and thickness of rationally oriented {100}Al plate/lath-shaped and Al rod-shaped precipitates in an age-hardenable Al-Cu-Mg- Si alloy have been examined quantitatively. An appropriate procedure of the plate- and rodshaped precipitate separation was suggested to determine the precipitate parameters as well as their distribution histograms using bright- (BF) and dark-field (DF) transmission electron microscopy (TEM) images taken in the Al and Al zone axes (ZA

The coarsening behavior of strengthening particles in an Al–Cu–Mg–Ag alloy during creep

The coarsening behavior of strengthening particles has been studied in a peak-aged Al–Cu–Mg–Ag alloy during creep at 150 ◦C and 165 ◦

The deformation behavior of the {111}Al plates in an Al-Cu-Mg-Ag alloy

The deformation behavior of {111}Al Ω plates has been analyzed in an Al-Cu-Mg-Ag alloy after creep tests to fracture by atomic-resolution scanning transmission electron microscopy (STEM

μSR study of Al-0.67%Mg-0.77%Si alloys

Zero-field muon spin relaxation measurements were carried out with Al-0.67%Mg- 0.77%Si alloys in the temperature range from 20 K to 300 K. Observed relaxation spectra were compared with the relaxation functions calculated by a Monte Carlo simulation with four fitting parameters: the dipolar width, trapping rate, detrapping rate and fraction of initially trapped muons. From the fitting, the temperature variations of the trapping rates reveal that there are three temperature regions concerning muon kinetics. In the low temperature region below 120 K, muons appeared to be trapped in a shallow potential yielded by dissolved Mg atoms, and thus little effect of heat treatment of the samples was observed, while in the mid and hightemperature regions, the trapping rates clearly depended on the heat treatment of the samples suggesting muon-cluster and/or muon-vacancy interactions

Edge interfaces of the Ω plates in a peak-aged Al-Cu-Mg-Ag alloy

The coherent edge interface structures of the relatively thin {111}Al Ω plates have been analyzed in a peak-aged Al-Cu-Mg-Ag alloy by atomic-resolution scanning transmission electron microscopy (STEM). Analysis of STEM images showed that these edge interfaces can deviate from their orthogonal orientations to the broad plate surface

Velocity-selected production of 2S3 metastable positronium

Positronium in the 2 3 S metastable state exhibits a low electrical polarizability and a long lifetime (1140 ns), making it a promising candidate for interferometry experiments with a neutral matter-antimatter system. In the present work, 2 3 S positronium is produced, in the absence of an electric field, via spontaneous radiative decay from the 3 3 P level populated with a 205-nm UV laser pulse. Thanks to the short temporal length of the pulse, 1.5 ns full width at half maximum, different velocity populations of a positronium cloud emitted from a nanochanneled positron-positronium converter were selected by delaying the excitation pulse with respect to the production instant. 2 3 S positronium atoms with velocity tuned between 7 7 10 4 ms 121 and 10 7 10 4 ms 121 were thus produced. Depending on the selected velocity, a 2 3 S production efficiency ranging from 3c0.8% to 3c1.7%, with respect to the total amount of emitted positronium, was obtained. The observed results give a branching ratio for the 3 3 P-2 3 S spontaneous decay of (9.7 \ub1 2.7)%. The present velocity selection technique could allow one to produce an almost monochromatic beam of 3c1 7 10 3 2 3 S atoms with a velocity spread of &lt;10 4 ms 121 and an angular divergence of 3c50 mrad

Gravity and antimatter: The AEgIS experiment at CERN

open62siFrom the experimental point of view, very little is known about the gravitational interaction between matter and antimatter. In particular, the Weak Equivalence Principle, which is of paramount importance for the General Relativity, has not yet been directly probed with antimatter. The main goal of the AEgIS experiment at CERN is to perform a direct measurement of the gravitational force on antimatter. The idea is to measure the vertical displacement of a beam of cold antihydrogen atoms, traveling in the gravitational field of the Earth, by the means of a moiré deflectometer. An overview of the physics goals of the experiment, of its apparatus and of the first results is presented.openPagano D.; Aghion S.; Amsler C.; Bonomi G.; Brusa R.S.; Caccia M.; Caravita R.; Castelli F.; Cerchiari G.; Comparat D.; Consolati G.; Demetrio A.; Noto L.D.; Doser M.; Evans A.; Fani M.; Ferragut R.; Fesel J.; Fontana A.; Gerber S.; Giammarchi M.; Gligorova A.; Guatieri F.; Haider S.; Hinterberger A.; Holmestad H.; Kellerbauer A.; Khalidova O.; Krasnicky D.; Lagomarsino V.; Lansonneur P.; Lebrun P.; Malbrunot C.; Mariazzi S.; Marton J.; Matveev V.; Mazzotta Z.; Muller S.R.; Nebbia G.; Nedelec P.; Oberthaler M.; Pacifico N.; Penasa L.; Petracek V.; Prelz F.; Prevedelli M.; Ravelli L.; Rienaecker B.; Robert J.; Rohne O.M.; Rotondi A.; Sandaker H.; Santoro R.; Smestad L.; Sorrentino F.; Testera G.; Tietje I.C.; Widmann E.; Yzombard P.; Zimmer C.; Zmeskal J.; Zurlo N.Pagano, D.; Aghion, S.; Amsler, C.; Bonomi, G.; Brusa, R. S.; Caccia, M.; Caravita, R.; Castelli, F.; Cerchiari, G.; Comparat, D.; Consolati, G.; Demetrio, A.; Noto, L. D.; Doser, M.; Evans, A.; Fani, M.; Ferragut, R.; Fesel, J.; Fontana, A.; Gerber, S.; Giammarchi, M.; Gligorova, A.; Guatieri, F.; Haider, S.; Hinterberger, A.; Holmestad, H.; Kellerbauer, A.; Khalidova, O.; Krasnicky, D.; Lagomarsino, V.; Lansonneur, P.; Lebrun, P.; Malbrunot, C.; Mariazzi, S.; Marton, J.; Matveev, V.; Mazzotta, Z.; Muller, S. R.; Nebbia, G.; Nedelec, P.; Oberthaler, M.; Pacifico, N.; Penasa, L.; Petracek, V.; Prelz, F.; Prevedelli, M.; Ravelli, L.; Rienaecker, B.; Robert, J.; Rohne, O. M.; Rotondi, A.; Sandaker, H.; Santoro, R.; Smestad, L.; Sorrentino, F.; Testera, G.; Tietje, I. C.; Widmann, E.; Yzombard, P.; Zimmer, C.; Zmeskal, J.; Zurlo, N

The AEgIS experiment at CERN: Measuring antihydrogen free-fall in earth's gravitational field to test WEP with antimatter

The AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) experiment is designed with the objective to test the weak equivalence principle with antimatter by studying the free fall of antihydrogen in the Earth's gravitational field. A pulsed cold beam of antihydrogen will be produced by charge exchange between cold Ps excited in Rydberg state and cold antiprotons. Finally the free fall will be measured by a classical moir\ue9 deflectometer. The apparatus being assembled at the Antiproton Decelerator at CERN will be described, then the advancements of the experiment will be reported: positrons and antiprotons trapping measurements, Ps two-step excitation and a test-measurement of antiprotons deflection with a small scale moir\ue9 deflectometer