Phase transformation and characterization of 3D reactive microstructures in nanoscale Al/Ni multilayers

Reactive multilayer systems represent an innovative approach for potential usage in chip joining applications. As there are several factors governing the energy release rate and the stored chemical energy, the impact of the morphology and the microstructure on the reaction behavior is of great interest. In the current work, 3D reactive microstructures with nanoscale Al/Ni multilayers were produced by alternating deposition of pure Ni and Al films onto nanostructured Si substrates by magnetron sputtering. In order to elucidate the influence of this 3D morphology on the phase transformation process, the microstructure and the morphology of this system were characterized and compared with a flat reactive multilayer system on a flat Si wafer. The characterization of both systems was carried out before and after a rapid thermal annealing treatment by using scanning and transmission electron microscopy of the cross sections, selected area diffraction analysis, and differential scanning calorimetry. The bent shape of multilayers caused by the complex topography of silicon needles of the nanostructured substrate was found to favor the atomic diffusion at the early stage of phase transformation and the formation of two intermetallic phases Al0.42Ni0.58 and AlNi3, unlike the flat multilayers that formed a single phase AlNi after reaction

Physics Beyond Colliders at CERN

The CERN Physics Beyond Colliders (PBC) study group was created in 2016 to explore the CERN and European potential for experiments complementary to those investigating the high-energy frontier at present and future large colliders. It currently supports proponents and CERN scientific committees in the preparation and subsequent review of such projects.The first lecture will introduce the field with a comprehensive experimental overview of the PBC landscape, with emphasis on projects proposed to be located at CERN. The second and third lectures will deal with the accelerator, infrastructure and technology aspects of the proposed projects, sharing the focus between LHC injectors (2nd lecture) and projects connected to the LHC (3rd lecture). The last lecture will address the specific theoretical motivations of PBC projects within the current worldwide landscape of open questions in particle physics.</p

St. John's Daily Star, 1920-12-31

The St. John's Daily Star was published daily except Sunday between 17 April 1915 - 23 July 1921

Cell therapies for inflammatory bowel diseases

Editorial.Peer reviewe