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Physical Sciences and Mathematics

Old Dominion University

Electrical & Computer Engineering Faculty Publications

Articles 1 - 7 of 7

Full-Text Articles in Engineering Science and Materials

Nb₃Sn Coating Of A 2.6 Ghz Srf Cavity By Sputter Deposition Technique, M. S. Shakel, Wei Cao, H. Elsayed-Ali, G. V. Eremeev, U. Pudasaini, A. M. Valente-Feliciano Jan 2022

Nb₃Sn Coating Of A 2.6 Ghz Srf Cavity By Sputter Deposition Technique, M. S. Shakel, Wei Cao, H. Elsayed-Ali, G. V. Eremeev, U. Pudasaini, A. M. Valente-Feliciano

Electrical & Computer Engineering Faculty Publications

Nb₃Sn is of interest as a coating for SRF cavities due to its higher transition temperature Tc ~18.3 K and superheating field Hsh ~400 mT, both are twice that of Nb. Nb₃Sn coated cavities can achieve high-quality factors at 4 K and can replace the bulk Nb cavities operated at 2 K. A cylindrical magnetron sputtering system was built, commissioned, and used to deposit Nb₃Sn on the inner surface of a 2.6 GHz single-cell Nb cavity. With two identical cylindrical magnetrons, this system can coat a cavity with high symmetry and uniform thickness. Using Nb-Sn multilayer sequential sputtering followed by …

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Magnetron Sputtering Of Nb3Sn For Srf Cavities, Md. N. Sayeed, H. Elsayed-Ali, G. V. Eremeev, M. J. Kelley, U. Pudasaini, C. E. Reece Jan 2018

Magnetron Sputtering Of Nb3Sn For Srf Cavities, Md. N. Sayeed, H. Elsayed-Ali, G. V. Eremeev, M. J. Kelley, U. Pudasaini, C. E. Reece

Electrical & Computer Engineering Faculty Publications

Nb3Sn is a potential candidate for surface material of SRF cavities since it can enable the cavity to operate at higher temperatures with high quality factor and at an increased accelerating gradient. Nb-Sn films were deposited using magnetron sputtering of individual Nb and Sn targets onto Nb and sapphire substrates. The as-deposited films were annealed at 1200 °C for 3 hours. The films were characterized for their structure by X-ray Diffraction (XRD), morphology by Field Emission Scanning Electron Microscopy (FESEM), and composition by Energy Dispersive X-ray Spectroscopy (EDS) and Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS). The …

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Optical Detection Of Melting Point Depression For Silver Nanoparticles Via In Situ Real Time Spectroscopic Ellipsometry, S. A. Little, T. Begou, R. W. Collins, S. Marsillac Jan 2012

Optical Detection Of Melting Point Depression For Silver Nanoparticles Via In Situ Real Time Spectroscopic Ellipsometry, S. A. Little, T. Begou, R. W. Collins, S. Marsillac

Electrical & Computer Engineering Faculty Publications

Silver nanoparticle films were deposited by sputtering at room temperature and were annealed while monitoring by real time spectroscopic ellipsometry (SE). The nanoparticle dielectric functions (0.75 eV-6.5 eV) obtained by SE were modeled using Lorentz and generalized oscillators for the nanoparticle plasmon polariton (NPP) and interband transitions, respectively. The nanoparticle melting point could be identified from variations in the oscillator parameters during annealing, and this identification was further confirmed after cooling through significant, irreversible changes in these parameters relative to the as-deposited film. The variation in melting point with physical thickness, and thus average nanoparticle diameter, as measured by SE …

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Electronic And Structural Properties Of Molybdenum Thin Films As Determined By Real Time Spectroscopic Ellipsometry, J. D. Walker, H. Khatri, V. Ranjan, Jian Li, R. W. Collins, S. Marsillac Jan 2009

Electronic And Structural Properties Of Molybdenum Thin Films As Determined By Real Time Spectroscopic Ellipsometry, J. D. Walker, H. Khatri, V. Ranjan, Jian Li, R. W. Collins, S. Marsillac

Electrical & Computer Engineering Faculty Publications

Walker, J.D., Khatri, H., Ranjan, V., Li, J., Collins, R.W., & Marsillac, S. (2009). Electronic and structural properties of molybdenum thin films as determined by real-time spectroscopic ellipsometry. Applied Physics Letters, 94(14). doi: 10.1063/1.3117222

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Evolution Of The Band Structure Of Β-In2 S3−3x O3x Buffer Layer With Its Oxygen Content, N. Barreau, S. Marsillac, J. C. Bernède, L. Assmann May 2003

Evolution Of The Band Structure Of Β-In2 S3−3x O3x Buffer Layer With Its Oxygen Content, N. Barreau, S. Marsillac, J. C. Bernède, L. Assmann

Electrical & Computer Engineering Faculty Publications

The evolution of the band structure of β-In2 S3−3x O3x (BISO) thin films grown by physical vapor deposition, with composition x, is investigated using x-ray photoelectron spectroscopy. It is shown that the energy difference between the valence-band level and the Fermi level remains nearly constant as the optical band gap of the films increases. As a consequence, the difference between the conduction band level and the Fermi level increases as much as the optical band gap of the films. The calculation of the electronic affinity [ ] of the BISO thin films shows that it decreases linearly from 4.65 …

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Study Of A Growth Instability Of Γ-In[Sub 2]Se[Sub 3], C. Amory, J. C. Bernede, S. Marsillac Jan 2003

Study Of A Growth Instability Of Γ-In[Sub 2]Se[Sub 3], C. Amory, J. C. Bernede, S. Marsillac

Electrical & Computer Engineering Faculty Publications

γ-In[sub 2]Se[sub 3] thin film are deposited for various substrate temperatures in the range of 523–673 K. This study shows that at 573 and 673 K the thin films are well crystallized with grains aligned along the c axis. Between these temperatures, a domain of instability appears where the γ-In[sub 2]Se[sub 3] thin films have a randomly orientation and the c-lattice parameter increases. The presence of the metastable phase κ-In[sub 2]Se[sub 3], during the growth, can explain the existence of this domain of instability. The insertion of Zn during the preparation process allows us to stabilize the phase κ at …

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Textured Mos 2 Thin Films Obtained On Tungsten: Electrical Properties Of The W/Mos 2 Contact, E. Gourmelon, J. C. Bernède, J. Pouzet, S. Marsillac Jan 2000

Textured Mos 2 Thin Films Obtained On Tungsten: Electrical Properties Of The W/Mos 2 Contact, E. Gourmelon, J. C. Bernède, J. Pouzet, S. Marsillac

Electrical & Computer Engineering Faculty Publications

Textured films of molybdenum disulfide have been obtained by solid state reaction between the constituents in thin films form when a (200) oriented tungsten sheet is used as substrate. The crystallites have their c axis perpendicular to the plane of the substrate. The annealing conditions are T=1073K and t=30 min. The films are stoichoimetric and p type. Such highly textured films are achieved without foreign atom addition (Ni, Co...). It appears, as shown by x-ray photoelectron spectroscopy, that a thin WS2 layer is present at the interface W/MoS2. The crystallization process is discussed by a …

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