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in subjects: "Mass Spectra"

open access

Imaging with Mass Spectrometry: A SIMS and VUV-Photoionization Study of Ion-Sputtered Atoms and Clusters from GaAs and Au

A new mass spectrometry surface imaging method is presented in which ion-sputtered neutrals are postionized by wavelength-tunable vacuum ultraviolet (VUV) light from a synchrotron source. Mass spectra and signal counts of the photoionized neutrals from GaAs (100) and Au are compared to those of the secondary ions. While clusters larger than dimers are more efficiently detected as secondary ions, certain species, such as As2, Au and Au2, are more efficiently detected through the neutral channel.… more

Date: December 5, 2008

Creator: Takahashi, Lynelle; Zhou, Jia; Wilson, Kevin R.; Leone, Stephen R. & Ahmed, Musahid

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Desorption Dynamics, Internal Energies and Imaging of Organic Molecules from Surfaces with Laser Desorption and Vacuum Ultraviolet (VUV) Photoionization

There is enormous interest in visualizing the chemical composition of organic material that comprises our world. A convenient method to obtain molecular information with high spatial resolution is imaging mass spectrometry. However, the internal energy deposited within molecules upon transfer to the gas phase from a surface can lead to increased fragmentation and to complications in analysis of mass spectra. Here it is shown that in laser desorption with postionization by tunable vacuum ultravi… more

Date: April 5, 2011

Creator: Kostko, Oleg; Takahashi, Lynelle K. & Ahmed, Musahid