Thesis (Ph. D.)--Syracuse University, 2009. / "Publication number: AAT 3385840."

<p>We are interested in the transition from an amorphous material to a polycrystalline structure. Previous research done by our group introduced a modified Random Nucleation and Growth model to describe this phenomenon. Besides the nucleation rate, its importance in the grain size distribution (GSD) having long been established, we introduced an effective time dependent growth rate, postulated the analytic form, and ascertained its effect on the GSD to match experimental data. Not only would we like to continue to substantiate this form, we wish also to determine how this rate depends on the fundamental parameters of the model. To achieve this, we have developed a numerical simulation in two dimensions, based on the premises of the model, to simulate crystallization in thin films. Not only does the simulation produce data that matches the analytical results of the nucleation rate and volume fraction available for nucleation, it also fits well with the postulated growth rate. This suggests the validity of the introduced effective growth rate and the functionality of the simulation for studying this process. </p>

The rapid progress of the field of ultracold atoms during the past two decades has set new milestones in our control over matter. By cooling dilute atomic gases and molecules to nano-Kelvin temperatures, novel quantum mechanical states of matter can be realized and studied on a table-top experimental setup while bulk matter can be tailored to faithfully simulate abstract theoretical models. Two of such models which have witnessed significant experimental and theoretical attention are (1) the two-component Fermi gas with resonant $s$-wave interactions, and (2) the single-component Fermi gas with dipole-dipole interactions. This thesis is devoted to studying the non-equilibrium collective dynamics of these systems using the general framework of quantum kinetic theory. / Physics

The fractional quantum Hall effect occurs when an extremely clean 2-dimensional fermion gas is subject to a magnetic field. This simple set of circumstances creates phenomena, such as edge reconstruction and fractional statistics, that remain subjects of experimental study 30 years after the discovery of the fractional quantum Hall effect. This thesis investigates the properties of excitations of the fractional quantum / Physics

Thesis (Ph.D.)--Syracuse University, 2008. / "Publication number: AAT 3323091."

Thesis (Ph. D.)--Syracuse University, 2009. / "Publication number: AAT 3381572."

Part I of this thesis deals with a brief historical review on diamond together with the studies made on crystal growth with the existing information on diamond. Part II deals with the experimental techniques employed for the present investigation including an interference technique whereby, it has been shown for the first time, that very sharp multiple-beam interference fringes can be produced with a high power 3 mm. lens of numerical aperture 0.95. The optical conditions necessary to secure high definition in the fringes are discussed together with the arrangement used which can resolve a lateral extension about 0.7 and a depth of 50 A0. Volume elements as small as 5 x 10 cc. can be resolved. Part III deals with the optical studies of growth features on the octahedron faces of some diamonds. Some features of particular interest are described namely :-1 - A number of anomalies in trigons. These are discussed in detail.2 - An occasional mode of growth sheets is shown to operate on the octahedral faces of diamond which leads to the formation of six-sided growth features containing alternate angles of approximately 90[degrees] and 150[degrees]. It is shown that the edges of these are effectively parallel to the directions 431.These may possibly arise through intersections of (221) with (111)3 - A remarkable case of multiple linear processes has been observed on five faces of a well formed good octahedron. This has been well interpreted as due to crystallographic slip in diamond. Part IV deals with the microstructure on the dodecahedral faces of some diamonds. Some new surface structures are described. A mosaic structure exists. At least three main different structures for the (110) faces can possibly arise during the growth of diamond namely :-1 - Striated surfaces either smooth or coarse.2 - A network structure.3 - A parallelogram structure related to 2.These structures are described and discussed in detail.

Measurements of the Faraday rotation have been made, as a function of thickness, applied magnetic field, and crystal orientation, for light of wavelength 5461A in films of nickel 100 to 400A in thickness. Reviews are given of the phenomenon of the Faraday rotation with particular reference to ferromagnetic films; of epitaxy, especially of metallic layers; and of thin film ferromagnetism. Techniques were developed with the aim of producing nickel specimens in the form of pure, parallel-sided, monocrystalline films, so as to obtain measurements which were true properties of the nickel lattice Using electron microscopy and diffraction, conditions were established for the epitaxial growth of nickel by condensation from the vapour phase in vacuo, on the principal planes of rock salt and copper. Oriented films grown on rock salt were generally aggregated or discontinuous, prominently twinned on {111} planes, and contained numerous crystal faults. Films grown on (110) faces displayed features attributable to twinning on (111) and (111) planes, and an elongation of the crystallites in the 001 direction. Oriented films grown on coppersubstrates were continuous down to 100A thickness and relatively free from faults. The magneto-optic rotations were measured by means of a photoelectric polarimeter with a precision of better than 1/3'. The construction and use of the instrument are described in the thesis. Film thicknesses were determined by measurement of the area and mass of each film, assuming bulk density. A discontinuity in the graph of rotation versus applied magnetic field for films grown on copper was found to be explicable in terms of the bulk lattice properties. No significant dependence of rotation on thickness was observed for such films. The specific rotations for the 100, 110, and 111 directions were found to be respectively +79,000 + 2,000/cm.,+88,000+ - 3,000/cm., and+97,000+ 3,000/cm.

In the last fifteen years there has been a considerable increase in the knowledge of the optical properties of metal layers less than 1000 A thick, and the use of layers produced by evaporation or cathodic sputtering has become increasingly common for the determination of the optical constants of metals. In this work the interferometric method, originally due to Tolansky, for the determination of the relative phase changes occurring on reflexion at the surface of a metal layer has been further developed, and, coupled with a simple photoelectric device for the measurement of intensity changes, has been applied to the study of reflexion at a number of surfaces. The method requires slightly transparent layers of the metal to form a transmission interferometer, and it is therefore of particular importance to determine within what thickness limits the optical properties of these layers can be taken as characteristic of the metal in bulk form. To this end, a study of the variation with thickness of the characteristics of non-normal reflexion at thin silver layers has been made for thicknesses between 100 and 1000 A. Measurements have also been made using the technique of the optical constants of copper, tin, speculum, and a new tin-nickel alloy. Some interesting anomalies in the opticalproperties of evaporated layers of tin have been observed. The thesis commences with a treatment of the theory of reflexion at metal surfaces and layers, and the previous work in this field is reviewed, with particular reference to measurements on evaporated layers, and the variation of their properties with thickness. The evaporation equipment and procedure used are described, and the measurement of layer thicknesses critically discussed. The optical techniques are then described, the interferometric technique being analysed in detail. Finally the results of the experiments are mentioned and discussed.

A historical review of the use of powder patterns, polarized light and intorferometry to examine small vibrations is given. Suitably cut quartz crystals are used for an examination by these methods of the longitudinal vibrations of thin isotropic discs. Previous calculations of the frequencies and displacements for these modes of vibration are extended and the distribution of stress is computed numerically. The theory underlying the use of the three methods of observation Is discussed with particular reference to the examination of these stresses and displacements. It Is found that for sufficiently thin discs the primary stresses and displacements are substantially in agreement with theory, except for the presence in all cases of a coupled flexural mode having a particular symmetry dependent upon the symmetry of the longitudinal mode. Moreover, for those modes which do not have circular symmetry about the disc axis, there are always two frequencies of vibration for which the orientations of the vibratory systems have a particular relation, again dependent upon the particular modal symmetry. A theory is given whichadequately explains the coupling phenomena by reference to the cross shear strains which are due to the particular crystal symmetry of quartz and are not possible for isotropic media. In connection with the polarized light experiments, a theory of the dependence of the apparent rotatory power of quartz upon stress is developed and agrees well with an experimental test; some phenomena observed by earlier workers are explained on the basis of this theory. It is shown that there is good correlation between the three methods of observation but that the information yielded by any one method separately is likely to give an oversimplified representation of the state of vibration.