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Full-Text Articles in Physics
Investigating The Properties Of Superfluid He-4 Through Density Functional Calculations, Matthew Francis Dutra
Investigating The Properties Of Superfluid He-4 Through Density Functional Calculations, Matthew Francis Dutra
Doctoral Dissertations
We present a study of isotopically pure He-4 systems evaluated using helium density functional theory (He-DFT) with the intent of better understanding their ground state structural and energetic properties, particularly within the scope of singularly-doped helium droplets. We self-consistently solve for the density profiles and chemical potentials for a wide range of pure helium droplet sizes (up to 9500 atoms) via an imaginary time propagation method, and fit the resultant energetic data to a power law formula to be able to extrapolate values for even larger droplets. Subsequent calculations on singularly-doped droplets within the same size range yield accurate binding …
Elucidating Fundamental Mechanisms In Focused Electron- And Ion-Beam Induced Synthesis, Carlos M. Gonzalez
Elucidating Fundamental Mechanisms In Focused Electron- And Ion-Beam Induced Synthesis, Carlos M. Gonzalez
Doctoral Dissertations
A focused electron beam deposition process (FEBID) coupled with in-situ infrared pulsed laser assist (LA-EBID) has been implemented for higher purity tungsten nanowires using W(CO)6 [tungsten hexacarbonyl] as parent precursor gas. Nanowires made of Co from Co2(CO)8 [dicobalt octacarbonyl] and Pt from MeCpPtIVMe3 [trimethyl methylcyclopentadienyl platinum] have also been realized by using inert focused ion beams of helium and helium and neon, respectively. In all cases, higher electrical conductivities, higher purities and larger grain sizes have been obtained when compared with preceding traditional additive edit techniques. These new approaches will make possible successful nanoscale direct-write …
Radii And Neutron Correlations Of (6,8)He Within The Gamow Shell Model, Georgios Papadimitriou
Radii And Neutron Correlations Of (6,8)He Within The Gamow Shell Model, Georgios Papadimitriou
Doctoral Dissertations
We study the spatial correlations between halo neutrons in 6,8He within the complex-energy Gamow Shell Model (GSM). To this end, we calculate the neutron and proton radii, and two-neutron correlations in a large shell model space consisting of the 0p3/2 resonance and non-resonant p-sd scattering continuum. We use schematic forces and the finite-range Modified Minnesota interaction.
The calculated charge radii, corrected for the core polarization and spin-orbit effects, are compared to the values extracted from measured atomic isotope shifts.
We find that the charge radius of 6He primarily depends on the two-neutron separation energy and the shell-model …