IPAC2015 - List of Authors (Seibert, R.L.)

Paper	Title	Page
TUPMA004	Synthesis of Ultra-Thin Single Crystal MgO/Ag/MgO Multilayer for Controlled Photocathode Emissive Properties	1846
	D.G. Velázquez, R.L. Seibert, L.K. Spentzouris, J. Terry, Z.M. Yusof Illinois Institute of Technology, Chicago, Illinois, USA
	Photocathode emission properties are critical for electron beam applications such as photoinjectors for free electron lasers (FEL) and energy recovery Linacs (ERL). We investigate whether emission properties of photocathodes can be manipulated through the engineering of the surface electronic structure. The multilayers described here have been predicted to have emission properties in correlation with the film thickness. This paper describes how ultra-thin multilayered MgO/Ag/MgO films in the crystallographic orientations (001) and (111) multilayers were synthesized and characterized. Preliminary results of work function measurements are provided. Films were grown by pulsed laser deposition at 130 °C for the (001) orientation and 210 °C for the (111) orientation at a background pressure of ~ 5×10^-9 Torr. Epitaxial growth was monitored in-situ using reflection high-energy electron diffraction, which showed single crystal island growth for each stage of the multilayer formation. Photoelectron spectroscopy was used to track the chemical state transition from Ag to MgO during the deposition of successive layers. The Kelvin probe technique was used to measure the change in contact potential difference, and thus work function, for various MgO layer thicknesses in comparison with bare single crystal Ag(001)and Ag(111) thin films. The work function was observed to reduce with increasing thickness of MgO from 0 to 4 monolayers as much as 0.89 eV and 0.72 eV for the (001) and (111) orientations, respectively. Photoelectron spectra near the Fermi level revealed electron density shifts toward zero binding energy for the multilayered surfaces with respect to the clean Ag surfaces.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA004
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Paper

Title

Page

Synthesis of Ultra-Thin Single Crystal MgO/Ag/MgO Multilayer for Controlled Photocathode Emissive Properties

1846

D.G. Velázquez, R.L. Seibert, L.K. Spentzouris, J. Terry, Z.M. Yusof
Illinois Institute of Technology, Chicago, Illinois, USA

Photocathode emission properties are critical for electron beam applications such as photoinjectors for free electron lasers (FEL) and energy recovery Linacs (ERL). We investigate whether emission properties of photocathodes can be manipulated through the engineering of the surface electronic structure. The multilayers described here have been predicted to have emission properties in correlation with the film thickness. This paper describes how ultra-thin multilayered MgO/Ag/MgO films in the crystallographic orientations (001) and (111) multilayers were synthesized and characterized. Preliminary results of work function measurements are provided. Films were grown by pulsed laser deposition at 130 °C for the (001) orientation and 210 °C for the (111) orientation at a background pressure of ~ 5×10^-9 Torr. Epitaxial growth was monitored in-situ using reflection high-energy electron diffraction, which showed single crystal island growth for each stage of the multilayer formation. Photoelectron spectroscopy was used to track the chemical state transition from Ag to MgO during the deposition of successive layers. The Kelvin probe technique was used to measure the change in contact potential difference, and thus work function, for various MgO layer thicknesses in comparison with bare single crystal Ag(001)and Ag(111) thin films. The work function was observed to reduce with increasing thickness of MgO from 0 to 4 monolayers as much as 0.89 eV and 0.72 eV for the (001) and (111) orientations, respectively. Photoelectron spectra near the Fermi level revealed electron density shifts toward zero binding energy for the multilayered surfaces with respect to the clean Ag surfaces.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUPMA004

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)