Scandium-based hexagonally-closed packed multi-component alloys

Since their early development, High-Entropy Alloys have fueled the investigation of exotic metal combinations. Here, we present a strategy for the rational design of a library for multi-component alloys based on six hcp-structured metals. Seven five- and six-component equimolar alloys based on Co, Gd, Y, Sc, Ti and Zr were prepared via induction melting and characterized by PXRD, SEM–EDX and Vickers hardness. They all present ternary hexagonal phases (ScTiZr or GdScY) co-existing with one or more cubic phases and intermetallic compounds. Both ScTiZr and GdScY appear promising as the starting point for new single-phase High-Entropy Alloys families

SEARCH FOR LEPTOQUARKS AND OTHER NEW PARTICLES WITH LEPTON - HADRON SIGNATURE IN e+ e- INTERACTIONS

Using the JADE detector at PETRA, a search for hadronic events with isolated leptons in e$^+$e$^-$ annihilation was performed. No evidence was found for the production of leptoquarks or color octet leptons and mass limits were obtained. Three hadronic events, each of them with two isolated muons, were detected and found to be in agreement with predictions of the α$^4$ QED process e$^+$e$^−$ → qq¯μ+μ−. At the highest PETRA energies,46.30Gev≦$\sqrt s$ ≦46.78, five events with low thrust,T<0.8, and a muon at a large angle with respect to the thrust axis, |cos δ|<0.7, were observed. The number of such events expected from an extrapolation of control data at lower energies is 0.56±0.18. No satisfactory explanation for the excess in terms of background could be found. A corresponding excess of electron events was not seen