STP1141: The Role of Valence-Band Excitation in Laser Ablation of KCl

    Haglund, RF
    Vanderbilt University, Nashville, TN

    Tang, K
    Vanderbilt University, Nashville, TN

    Bunton, PH
    Austin Peay State University, Clarksville, TN

    Wang, L-J
    University of Tennessee, Chattanooga, TN

    Pages: 12    Published: Jan 1991


    Abstract

    We present recent measurements of excited-atom and ion emission from KCl surfaces illuminated by vacuum-ultraviolet synchrotron radiation (hv = 8–28 eV) and ultraviolet laser light (hv = 4 eV). At low intensities characteristic of the synchrotron experiments, excited atoms are desorbed by simple valence-band excitation process involving the metallization of the KCl surface. At the higher intensities typical of laser desorption and ablation, we observe a strong decrease in K* emission as a function of the number of laser shots, but an essentially constant yield of Cl*. K+ and Cl- emission at high intensities show similar behavior. The energetics of these desorption phenomena can be treated in a bond-orbital model which shows that creation of a single valence hole is sufficient to excite an ion to an anti-bonding state.


    Paper ID: STP23620S

    Committee/Subcommittee: F01.19

    DOI: 10.1520/STP23620S


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