Martin Peter, M.W.P. Strandberg. / "August 26, 1957." "Also published as Technical report no. 1 on Contract DA36-039-sc-73014." / Bibliography: p. 49-50. / U.S. Army Signal Corps Contract No. DA36-039-sc-64637 Dept. of the Army Task 3-99-06-108 Project 3-99-00-100

Thesis (Ph. D.)--University of Oregon, 2000. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 110-113). Also available for download via the World Wide Web; free to University of Oregon users.

Van der Waals molecules are complexes of two or more atoms or molecules bound by weak intermolecular forces rather than a conventional chemical bond. This thesis contains a high resolution molecular beam study of the rotational spectra of two such species, ArNO and NeNO. A new hamiltonian is presented to account for the spectra of these open-shell complexes. The theory is similar to that already known for the uncomplexed diatom, nitric oxide, but is modified to an asymmetric top form appropriate for these non-linear species. Two novel interactions require inclusion. The first models a slight quenching of the NO orbital angular momentum by the rare gas atoms. The second is a large centrifugal distortion associated with the effects of the bending motion on the projection of the electronic angular momentum on the complex's a-inertial axis. A comparatively rich, though incomplete, spectrum is obtained for ArNO. Most of the transitions that originate from the lower rotational states are assigned and fitted to within a few MHz using the modified open-shell hamiltonian. Possible sources are suggested for the origins of the small residual errors between the observed and calculated transition frequencies. A vibrationally-averaged structure is derived from the fitted molecular parameters indicating an equilibrium geometry which is quite close to a T-shape. The hyperfine structure in the spectrum which is associated with the ¹⁴ N nucleus is well fitted by the hamiltonian; however, the magnetic hyperfine parameters are significantly perturbed from the values that best fit the lambda-doubling spectrum of the uncomplexed diatom. The implications of this with respect to the nature of the rare gas-nitric oxide intermolecular interaction are discussed. Greater experimental difficulties are encountered in trying to record the radiofrequency and microwave spectrum of NeNO and so fewer transitions have been measured than for ArNO. A partial analysis yields approximate values for the structural parameters. The complex exhibits a larger deviation from the T-shaped geometry than is observed for ArNO. The spectrum also provides an estimate of the magnitude of the quenching of the orbital angular momentum. The quenching interaction is somewhat larger in the neon complex.

Thesis (Ph. D.)--Physics, Georgia Institute of Technology, 2007. / de Heer, Walter A., Committee Chair ; Chou, Meiyin, Committee Member ; Whetten, Robert L., Committee Member ; First, Phillip N., Committee Member ; Pummer, Earl Ward, Committee Member.

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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 1980. / MICROFICHE COPY AVALABLE IN ARCHIVES AND SCIENCE. / Vita. / Includes bibliographical references. / by Edmond Joseph Murphy, Jr. / Ph.D.

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Physics, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Vita. / Bibliography: leaves 140-145. / by Walter Peter Lapatovich. / Ph.D.

Ferroelectric and ferromagnetic alloy clusters are produced and studied in molecular beams. Nb clusters doped with 1-3 impurity atoms are ferroelectric with low transition temperatures. The alloy clusters with an even number of valence electrons have larger dipole moments than those with odd number of valence electrons. The ferroelectricity is suppressed by magnetic impurities or thermal excitations, and is enhanced by Au and Al doping. The observations strongly suggest that electron-pairing interactions exist in Nb clusters, which indicates Cooper pairing in clusters. The magnetic moments of Co clusters doped with small fraction of Mn,V and Al are studied and compared with those of the bulk alloys. CoMn alloy clusters have enhanced average magnetic moments with Mn doping, which is opposite to the behavior of bulk CoMn. CoV and CoAl alloy clusters behave similarly to their bulk counterparts. We explain the experimental results using the virtual-bound-state model. Finally, the magnetic properties of BiMn clusters are studied in molecular beams. The Mn local moments are found to couple ferromagnetically or ferrimagnetically depending on the composition of the clusters.

Title: Implementation of ion imaging technique in experiments with free molecules, clusters and nanoparticles Author: Jaroslav Kočišek Department: Department of Surface and Plasma Science Supervisor: Mgr. Michal Fárník, PhD., DSc., Ústav fyzikální chemie J. Hey- rovského, AV ČR, v.v.i. Abstract: The experimental work is focused on implementation of novel tech- niques to study clusters and nanoparticles in molecular beams. A new exper- imental system was tested, which combines the technique of velocity map ion imaging with pulsed molecular beam source. The same method and new mass spectrometer were implemented on the apparatus with molecular beam of size selected clusters. The new methods were used to study environmental effects on photo and electron induced chemistry. The most important results concerns on influence of expansion conditions on the structure of formed neutral clusters of HBr and C2H2. Results of experiments with HNO3 and CF2Cl2 molecules are then crucial for understanding heterogeneous processes in the Stratosphere. Keywords: ion imaging, mass spectrometry, molecular beams, photochemistry, nanoparticles

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