## Electronic Theses and Dissertations

1989

Dissertation

Ph.D.

Physics

Physics, Atomic.

CC BY-NC-ND 4.0

#### Abstract

Extensive and previously unknown fluorescence and excitation spectra of the HgZn excimer have been observed and correlated with a potential energy (PE) diagram drawn and labelled according to Hund's case (c). The spectra were excited in a Hg-Zn mixture contained in a quartz vapour cell by successive pulses from two dye lasers using the pump-and-probe method, and were recorded using techniques of time-resolved fluorescence spectroscopy. The reservoir states, which became populated by the pump pulse, were found to be the A1, AO$\sp-$ and AO$\sp+$ states. The fluorescence band at 4750 A, which has a 6$\mu$s lifetime and was first observed by Eden$\sp1$, was recognized as due to bound-continuum decays from the A1 and AO$\sp+$ states to the XO$\sp+$ ground state, and its time-evolution was recorded at various cell temperatures. Subsequent absorption of the probe pulse resulted in the excitation of several higher-lying states which were identified as the CO$\sp+$, E1, F1 and EO$\sp-$ states. Several excitation spectra were recorded and assigned to CO$\sp+$ $\gets$ AO$\sp+$, E1 $\gets$ AO$\sp-$, E1 $\gets$ AO$\sp+$, F1 $\gets$ AO$\sp+$, EO$\sp-$ $\gets$ A1 and EO$\sp-$ $\gets$ AO$\sp-$ transitions. UV fluorescence bands, which were observed centered at 2500 A, 2270 A and 2230 A, consisted of well-resolved Condon internal diffraction patterns, and were correlated with appropriate upper-state vibrational wave functions. They were attributed to bound-continuum transitions from the CO$\sp+$, E1 and F1 states to the XO$\sp+$ ground state, respectively. Bound-bound fluorescence bands were observed at 4288 A, 4122 A, 4236 A and 4637 A, and were identified as arising from F1 $\to$ AO$\sp+$, EO$\sp-$ $\to$ Al, EO$\sp-$ $\to$ AO$\sp-$ and EO$\sp-$ $\to$ BO$\sp-$ transitions, respectively. A predissociation effect, which gave rise to Hg 4916 A emission, was also observed and interpreted. Analysis of the experimental data yielded vibrational constants, relative energies and relative internuclear separations of the PE minima for the various states. There is good agreement between the measured transition energies and the values estimated from the PE diagram. Source: Dissertation Abstracts International, Volume: 50-03, Section: B, page: 0996. Thesis (Ph.D.)--University of Windsor (Canada), 1989.

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