SRF2011 - List of Authors (Zasadzinski, J.)

Paper	Title	Page
THPO072	Raman Spectroscopy as a Probe of Surface Oxides and Hydrides on Niobium	912
	J. Zasadzinski IIT, Chicago, Illinois, USA B. Albee, S. Bishnoi, C. Cao Illinois Institute of Technology, Chicago, IL, USA G. Ciovati JLAB, Newport News, Virginia, USA L.D. Cooley, D.C. Ford Fermilab, Batavia, USA Th. Proslier ANL, Argonne, USA
	Funding: ANL, FNAL Raman microscopy/spectroscopy has been used in conjunction with AFM, tunneling and magnetic susceptibility to identify surface oxides and hydrides on annealed, recrystallized foils of high purity Nb and on single crystals of cavity grade Nb. Cold worked regions of the Nb foil as well as rough regions near grain boundaries showed clear evidence of ordered hydride phases which were identified by VASP phonon calculations. Cold worked regions also displayed enhanced surface paramagnetism. Surface enhanced Raman spectra have also been obtained using 1.0 nm Au depositon. The SERS spectra reveal hydride molecular species which are not observable by conventional Raman. These results indicate that Raman is a useful probe of Nb surfaces relevant for cavity performance

Paper

Title

Page

Raman Spectroscopy as a Probe of Surface Oxides and Hydrides on Niobium

912

J. Zasadzinski
IIT, Chicago, Illinois, USA
B. Albee, S. Bishnoi, C. Cao
Illinois Institute of Technology, Chicago, IL, USA
G. Ciovati
JLAB, Newport News, Virginia, USA
L.D. Cooley, D.C. Ford
Fermilab, Batavia, USA
Th. Proslier
ANL, Argonne, USA

Funding: ANL, FNAL
Raman microscopy/spectroscopy has been used in conjunction with AFM, tunneling and magnetic susceptibility to identify surface oxides and hydrides on annealed, recrystallized foils of high purity Nb and on single crystals of cavity grade Nb. Cold worked regions of the Nb foil as well as rough regions near grain boundaries showed clear evidence of ordered hydride phases which were identified by VASP phonon calculations. Cold worked regions also displayed enhanced surface paramagnetism. Surface enhanced Raman spectra have also been obtained using 1.0 nm Au depositon. The SERS spectra reveal hydride molecular species which are not observable by conventional Raman. These results indicate that Raman is a useful probe of Nb surfaces relevant for cavity performance