Corrosion behaviour of Mg−Gd−Y−Zn−Ag alloy components with different sizes after cooling

The corrosion behaviour of Mg−6Gd−3Y−1Zn−0.3Ag(wt.%)alloy components with different sizes after cooling was investigated.The alloys in the small components(SC)cooled fast,which were composed ofα-Mg matrix and coarse long-period stacking ordered(LPSO)phases.The alloys in the large components(LC)cooled slowly,and there were thin lamellar LPSO phases precipitating inside the grains,except forα-Mg matrix and coarse LPSO phases.The hydrogen evolution test revealed that the corrosion rate of LC sample was higher than that of SC sample.Electrochemical impedance spectroscopy(EIS)test showed that the surface film on LC alloys provided worse protection.The corrosion morphologies indicated that the precipitation of the thin lamellar LPSO phases in LC sample caused severe micro-galvanic corrosion,which accelerated the rupture of the surface film.

Roles of tensor force and pairing correlation in two-proton radioactivity of halo nuclei

The tensor force and pairing correlation effects on the two-proton radioactivity of^(18)Mg and^(20)Si with a pronounced two-proton halo are explored in the framework of spherical Skyrme-Hartree-Fock-Bogoliubov theory.It is shown that the halo sizes are enhanced with the increase in the strength of the tensor force and pairing correlation.Furthermore,the increasing halo sizes lead to the enhancement of diproton emission.Then,the tensor force is found to have a small influence on the two-proton decay energies,and the two-proton decay energies calculated with strong surface pairing are smaller than those with weak mixed pairing.Because the two-proton decay energies are relat-ively large,the predicted order of magnitude of half-lives within the effective liquid drop model is not sensitive to the decay energy variation caused by the tensor force and pairing correlation,which has a value of approximately 10^(-18)s.

Spin-1 pyrochlore antiferromagnets:Theory,model,and materials'survey

Pyrochlore magnets can be a unique platformn to demonstrate numerous important concepts and appli-cations of frustrated magnetic physics in modern condensed matter physics.Most works on pyrochlore magnets deal with the interacting spin-1/2 local moments,while much less works have studied the spin-1 systems.We here review the physics with interacting spin-1 local moments on the pyrochlore lattice to ilustrate the potentially interesting physics associated with spin-1 magnets.The generic pyrochlore spin-1 model includes the antiferromagnetic Heisenberg interaction,the Dzyaloshinski-Moriya interaction and the single ion spin anisotropy.The global phase diagram of this generic spin model is reviewed,and the relation between different quantum phases in the phase diagram is clari-fied.The critical properties of the transition from the parent quantum paramagnet to the proximate orders are discussed.The presence of quantum order by disorder in the parts of the ordered phases is analyzed.The elementary excitations with respect to the ground states are further reviewed,and the topological natures of these excitations are carefully addressed.The materials'relevance of the spin-1 pyrochlore magnets are finally reviewed.This review may provide insights about the interesting spin-1 local moments on frustrated systems.