In this work, the crystallographic structure and its changes under thermal treatment of different systems consisting of metal oxide nanoparticles is studied. The principal method used throughout the thesis is x-ray powder diffraction enriched with grazing incidence small angle x-ray scattering when the nanoparticles form an ordered structure or with x-ray absorption spectroscopy when additional information on local crystallographic structure is required. For all the systems the preparation conditions were optimized according to the crystallographic data for further applications.

In my essay I show Fourier transform theory and applications in context with difraction theory especially Fraunhofer difraction. In part of the experiment, I set up an optical signal processing system. I take the Fourier transform of an input signal using a lens, filter the transform by placing various filters at the Fourier plane, and take the inverse transform. A simple optical bench consists of a laser, to produce a parallel, monochromatic beam which illuminates a specific area of the micrograph. Lens to focus the Fraunhofer diffraction pattern in the back focal plane of the lens. Mask transit contrived light or block out most of the noise in the diffraction pattern arising from image features. A reconstruction lens, placed behind the mask, refocuses the unobstructed rays and forms a filtered image. Optical diffraction provides useful information about the geometrical arrangement of subunits in the specimen. I make experiments for attestation on elementary objects and real images in mathematic program Matlab. From knowledge Fraunhofer difraction and organization of experiment I calculated size of circular object. I show practical using of Fraunhofer difraction and optical filtration. My essay give good introduction to the theory and techniques of optical filtration.

This master´s thesis deals with communication which is provided by optical devices. Optical wireless links are enforced due to high bit rate, responsibility and noise immunity. Main part of this master´s project is devoted to optical fibre, its characteristic and its usage in laser transmitter.

The Master's thesis deals with the determination of measurement method of deflection the axis of the optical beam from its ideal position, which is caused by action of force of strong winds affecting the positional stability of the building or supporting structure (tower) used for placement of FSO links'heads. The thesis informs the readers about the other causes of deflection of beam axis in a real environment, about methods of determining the position of the beam axis in the plane perpendicular to the beam axis and the basic properties and parameters of the Gauss beams, including the phenomenon of diffraction on the output aperture of the laser transmitter.

Title: The magnetocrystalline anizotropy in the TbTX compounds Author: Milan Klicpera Department: Department of Condensed Matter Physics Supervisor: doc. Mgr. Pavel Javorský, Dr. Supervisor's e-mail address: javor@mag.mff.cuni.cz Abstract: The subject of this work is the study of structural, magnetic and trans- port properties of the TbNi(Al,In) series to finding connections between magne- tocrystalline anisotropy and lattice parameters of the structure of the TbTX com- pounds. Polycrystalline TbNiAl1−xInx samples were prepared by melting. The phase and crystal structure analysis were provided on samples. We performed the measurements of the magnetization, susceptibility, specific heat, resistivity, low temperature X-ray diffraction and powder neutron diffraction. From the neutron diffraction data we refined lattice parameters and propagation vectors of the series. The main propagation is (000) and second weaker component has the propagation vector (1 2 0 1 2 ). The change of the magnetocrystalline anisotropy from uniaxial to planar type occurs for compounds with x between 0.4 and 0.5. Keywords: magnetization, X-ray and neutron diffraction, electrical resistivity.

Title: Study of new type of Ti-NT nanotubes that can be used as a filler in polymer matrix Author: Tereza Brunátová Department: Department of Condensed Matter Physics Supervisor: doc. RNDr. Radomír Kužel, CSc. Abstract: The subject of presented work has been devoted to a structure of titanate nanotubes which were prepared by hydrothermal treatment of TiO2 powder in NaOH solution. Structure determination was done mainly with two complementary methods - X-ray diffraction and transmision elec- tron microscopy. A influence of structure by changing particle size and crystal structure of the initial powder TiO2 was studied as well. Three different mod- els of nanotube structure were build. These models were used for a calculation of powder X-ray diffraction pattern and they were compared to experiment pattern. Keywords: titanates nanotubes, computer simulations of powder X-ray diffrac- tion patterns, X-ray diffracion, electron microscopy

The deformation mechanisms of commercially pure magnesium using advanced in-situ methods were investigated in the present work. Compression and tensile test were done at room temperature. Simultaneously, the neutron diffraction was measured and the acoustic emission was recorded. The microstructure of the deformed material was also studied by means of optical microscopy and electron back-scattered diffraction. These measurements provided information about twin nucleation and growth, microstructure changes and the influence of the orientation of grains on the number of twins and their shape. The values obtained were compared to the Elasto-Plastic Self-Consistent model, which provides information about the activity of deformation mechanisms. We focused on clarifying the influence of twinning activity on asymmetry between tensile and compression deformation.

The diffractive open charm production is studied using data from 2006-2007, when the leading proton measurement by H1 Very Forward Proton Spectrometer was provided. The charm production is tagged by the decay products of D∗ meson. The cross section of e+ p → e+ D∗ X p in photoproduction regime defined by the value of virtuality Q2 < 2 GeV is determined and corrected for the detector effects. The diffractive D∗ meson photoproduction cross section is compared with the hadron level MC Rapgap prediction based on diffractive parton distribution functions extracted from inclusive ep DIS measurements. Measurement of leading proton provides a unique opportunity to investigate the response of forward detectors for the diffractive events. Using such events, the performance of the large rapidity gap selection is examined.

The cross section of the diffractive process e+p → e+Xp is measured at a centre-of-mass energies of 319 GeV, where the system X contains at least two jets and the leading final state proton p is detected in the H1 Very Forward Proton Spectrometer. The measurement is performed in photoproduction defined by photon virtualities Q2 < 2 GeV2 and in deep-inelastic scattering with 4 GeV2 < Q2 < 80 GeV2 . The results are compared to next-to-leading order QCD calculations based on diffractive parton distribution functions as extracted from measurements of inclusive cross sections in diffractive deep- inelastic scattering. A collinear QCD factorization theorem is tested against the measured cross sections and their ratios. 1

The work is focused on developing testing methods for investigating of the deformation mechanisms of magnesium alloys. The work involves the measurement of in-situ acoustic emission and neutron diffraction and comparison to the theoretical models. Mg + 1wt.% Zr alloy was selected for investigation of the compression - tension asymmetry. Advanced analysis of acoustic emission and neutron diffraction data revealed activation of different slip systems during deformation. Moreover, the different evolution of twinning was explained. The same methods were used to investigate the aluminum influence on deformation mechanisms. The hardening of basal slip and twinning and increasing importance of prismatic slip was observed.