Comparison of Phase Separation Structures between Undercooled Cu–Fe and Cu–Co Alloys Solidified Under a Static Magnetic Field

An electromagnetic levitation technique superimposed with a static magnetic field was used to investigate the effects of the convection and cooling rate of levitated molten Cu80Fe20 alloy on the size and morphology of induced phase separation structures formed during undercooling. The obtained results were compared to our previous works on the Cu80Co20 alloy, in terms of the size and morphology of the phase-separated structures of dispersed Fe-rich phases. It was revealed that the Sauter mean diameter in the two systems followed the same trend, although the Co-rich phases were larger in size than the Fe-rich ones at higher static magnetic fields. Under a larger static magnetic field, the separated Co-rich phases in Cu–Co alloys had an elongated shape along the direction of the static magnetic field, while the Fe-rich phases in Cu–Fe remained almost spherical in shape. This difference in shapes was attributed to physical properties, particularly their magnetic susceptibility

Surface terminations control charge transfer from bulk to surface states in topological insulators

Abstract Topological insulators (TI) hold significant potential for various electronic and optoelectronic devices that rely on the Dirac surface state (DSS), including spintronic and thermoelectric devices, as well as terahertz detectors. The behavior of electrons within the DSS plays a pivotal role in the performance of such devices. It is expected that DSS appear on a surface of three dimensional(3D) TI by mechanical exfoliation. However, it is not always the case that the surface terminating atomic configuration and corresponding band structures are homogeneous. In order to investigate the impact of surface terminating atomic configurations on electron dynamics, we meticulously examined the electron dynamics at the exfoliated surface of a crystalline 3D TI (Bi $$_2$$ 2 Se $$_3$$ 3 ) with time, space, and energy resolutions. Based on our comprehensive band structure calculations, we found that on one of the Se-terminated surfaces, DSS is located within the bulk band gap, with no other surface states manifesting within this region. On this particular surface, photoexcited electrons within the conduction band effectively relax towards DSS and tend to linger at the Dirac point for extended periods of time. It is worth emphasizing that these distinct characteristics of DSS are exclusively observed on this particular surface

Studying the impact of deuteron non-elastic breakup on 93Zr + d reaction cross sections measured at 28 MeV/nucleon

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The deuteron is a loosely bound system that can easily break up into its constituent proton and neutron whilst in the presence of Coulomb and nuclear fields. Previous experimental studies have shown that this breakup process has a significant impact on residual-nucleus production from deuteron bombardment in the high-energy range of 50–210 MeV/nucleon. However, there remains a lack of cross-section data at energies below 50 MeV/nucleon. The current study determined 93Zr + d reaction cross sections under inverse kinematics at approximately 28 MeV/nucleon using the BigRIPS separator, OEDO beamline, and SHARAQ spectrometer. Cross sections from this research were compared with previous measurements and theoretical calculations. The experimental results show a large enhancement of the production cross sections of residual nuclei, especially those produced from a small number of particle emissions, compared to the proton-induced reaction data at simi- © The Author(s) 2023.11Nsciescopu