UNT Theses and Dissertations - 3 Matching Results

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Deep Minima and Vortices for Positronium Formation in Positron-Hydrogen and Positron-Helium Collisions

Description: This dissertation work is a study of positronium formation for positron-hydrogen and positron-helium collisions in the Ore gap (the energy region between the threshold for ground-state positronium formation and the first excitation level of the target atom) using variational K-matrices. We have fitted the K-matrices using multichannel effective range theories and using polynomials. Using the variational K-matrices and their fits, we have located zeros in the positronium-formation scattering amp… more
Date: May 2021
Creator: Alrowaily, Albandari Wanes
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Investigation of Room Temperature Soft Ferromagnetism in Indium Phosphide Substrate Synthesized via Low Energy Nickel Ion Implantation

Description: In this work, we have utilized an ion beam process known as gettering to migrate implanted Ni ions much deeper into the bulk substrate than their initial projected end of the range. The projected mean depth is known as Rp. The gettering effect is the most crucial part of the fabrication and we have found that for an H fluence of 3x 1016 cm-2 there is a threshold fluence of approximately 7.5 x 1015 cm-2 that cannot be surpassed if the gettering process is to be completed along with the substrat… more
Date: May 2021
Creator: Jones, Daniel C.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Modeling, Characterization, and Magnetic Behavior of Transition Metal Nanosystems Synthesized in Silicon Using Low Energy Ion Implantation

Description: Magnetic nano-clusters in silicon involving iron and cobalt were synthesized using low energy (50 keV) ion implantation technique and post-implantation thermal annealing. Before the irradiation, multiple ion-solid interaction simulations were carried out to estimate optimal ion energy and fluence for each experiment. For high-fluence low-energy irradiation of heavy ions in a relatively lighter substrate, modeling the ion irradiation process using dynamic code SDTrimSP showed better agreement w… more
Date: May 2021
Creator: Singh, Satyabrata
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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