This thesis concerns the characterization of novel materials by utilizing electron microscopy techniques. The examined materials contain cavities with certain attributes that enables desired properties for applications such as gas separation, catalysis and fuel cells. The specimens concerned herein belong to the following groups of materials: Metal oxides in the Sb-W-Mo-O system; ordered mesoporous silicas and carbons; hollow spheres containing Au-nanoparticles; zeolite LTA incorporated with mesopores; metal organic frameworks doped with nickel. With scanning electron microscopy (SEM) and transmission electron microscopy (TEM) you get vast possibilities within the field of characterization. This thesis utilizes conventional electron microscopy techniques such as imaging, energy-dispersive spectroscopy and electron diffraction as well as reconstruction techniques, such as exit-wave reconstruction, electron tomography and electron crystallography. Furthermore, the sample preparation technique cross-section polishing has been used in conjunction with low voltage SEM studies. The scientific approach is to gain knowledge of nano-sized cavities in materials, in particular their shape, size and content. The cavities often have irregularities that originates from the synthesis procedure. In order to refine the synthesis and to understand the properties of the material it is required to carefully examine the local variations. Therefore average characterization techniques such as crystallography needs to be combined with local examination techniques such as tomography. However, some of the materials are troublesome to investigate since they to some extent bring limitations to or gets easily damaged by the applied characterization technique. For the development of novel materials it is essential to find means of overcoming also these obstacles. / At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 6: Submitted.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1985. / Typescript. Vita. Includes bibliographical references (leaves 268-283).

Thesis (Ph.D.)--University of Melbourne, Dept. of Physics, 2005. / Typescript. Includes bibliographical references (leaves 205-223).

An atomic force microscope is an instrument that is capable of imaging magnetic, electric and van der Waals forces with a very high resolution. In this thesis, different methods for detecting the displacement of the force sensing lever in such an atomic force microscope are discussed. Special emphasis is given to optical detection methods that are used in conjunction with a vibrating lever. The three optical systems that are discussed are based on (1) the heterodyne interferometer, (2) the homodyne interferometer, and (3) a new design that utilizes feedback into a laser diode. Images of a hard disk drive head and of domains in a TbFeCo thin film sample that were obtained with the heterodyne system are presented. Also presented are images of domains in a different TbFeCo sample and of interdigital fingers that were collected with the novel laser diode system.

This work is based upon a series of quantitative morphological studies of the parathyroid glands of Mongolian gerbils and rats. Standard stereological methods were used on light and electron microscopical levels. Subclassification of the chief cells based on the staining affinity and electron density of the cytoplasm was not correlated with contents (volume and surface densities) of organelles. Compared to fixation by immersion, fixation by perfusion caused a remarkable reduction in the number of light chief cells and atrophic cells, indicating that the occurrence of those kind of cells is dependent on factors of artifactual nature. The early response of the parathyroid gland to altered concentrations of extracellular calcium was studied in vitro. At six hours of "incubation, enlargement of the Golgi zone (Golgi complex and presecretory granules), but unaltered endoplasmic reticulum, was seen in glands incubated in low (0,5 mM) compared to those incubated in high (3,0 mM) calcium concentrations. Prolonged hypocalcemia induced in vivo by intraperitoneal injections of ethylenediaminetetraacetate and calcium deficient diet for eight days, did not give rise to any major quantitative morphological changes in the individual parathyroid cell, and furthermore, the quantitative morphology of the parathyroid cell was unchanged in experimentally induced hyperparathyroidism (calcium deficient diet for 16 weeks). The morphological data do not support the opinion of a functional cycle in the parathyroid chief cell, but suggest that the early response of this cell to altered extracellular calcium may be funtional activities associated with the Golgi zone. / <p>S. 1-48: sammanfattning, s. 49-170: 5 uppsatser</p> / digitalisering@umu

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Transmission electron microscopy (TEM) is a powerful and versatile tool for investigating nanomaterials. In this thesis, various transmission electron microscopy techniques are used to study the chemical and structural features of different types of inorganic nanoparticles of well-defined morphologies as well as their assemblies. The synthesis of spherical and anisotropic nanoparticles (iron oxide nanocubes and other morphologies, gadolinium orthophosphate nanorods, tungsten oxide nanowires and nanorods, palladium nanospheres, and facetted iron-manganese oxides hybrid nanoparticles) using thermal decomposition of metal complex precursors in high-boiling point organic solvents and hydrothermal process are described in details. Electron diffraction tomography (3D EDT) is a recently developed technique that is used to investigate the 3D structure of crystalline materials. Reciprocal space volume reconstruction of 3D EDT data of thin WO3 nanowires assembled into nanorods revealed single crystal domains of hexagonal symmetry. Moreover, the use of 3D EDT enabled to identify and solve the structures of individual GdPO4 nanorods in a mixed phase powder. The use of 3D EDT was extended using small-angle diffraction mode to investigate the packing arrangements and defects in nanoparticle assemblies. A high concentration of planar defects found in different nanoparticle assemblies highlights the competition between the fcc and hcp arrangements during the assembly process. Iron-manganese oxides hybrid nanoparticles with different three-dimensional configurations, i.e. core|shell and asymmetric facetted dimers, were investigated using a combination of several electron microscopy techniques (HRTEM, SAED, STEM-HAADF, EFTEM, EELS). The growth of the facetted cubic MnO phase onto preformed Fe3O4 seed particles occurs preferentially along the Fe3O4 nanocube edges forming a well-oriented crystalline interface despite the lattice mismatch and defects. Atomic resolution monitoring of the structural changes in Mn3O4|Fe3O4 and Fe3O4|Mn3O4 core|shell nanoparticles induced by the electron beam revealed a strain relief mechanism at the interface involving inhomogeneous diffusion of cations and defects creation. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Manuscript. Paper 5: Manuscript.</p>