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Advanced gas deposition was used to make nanocrystalline gold films.

A new study aims to produce high quality nanocrystalline particles showing a solid solution, focusing on the magnetic properties of Ag-Mn nanoparticles and demonstrating an unambiguous spin glass state.

A study was conducted to analyze the influence of a YBa2CU3O(sub 7-x) buffer layer on the quality of rf magnetron sputtered epitaxial (001) SrTiO3 thin films on a LaAlO3 substrate. High resolution transmission electron spectroscopy was utilized to carry out the analysis. The film was oriented with the (001) axis parallel to the normal of the substrate surface. Results indicated that rubbed polyimide alignment layers promoted a surface pretilt of 0.5 degrees.

A study demonstrated that electron energy-loss spectroscopy in transmission electron microscopy is a useful technique for analysis of the high-frequency dielectric properties on a microstructural level. Changes in the low frequency dielectric function between Sr deficient and stoichiometric films were much larger compared to the changes in the high-frequency function. It was found that strain and compositional deviations from the bulk value resulted in decreased ability to withstand dielectric breakdown.

High resolution analytical transmission electron microscopy was employed to determine the properties of the structural features of light emitting Si/SiO2 multilayers. Complex dielectric function was extracted from the experimental single-scattering distribution by utilizing the Kramers-Kronig analysis. This indicated the presence of an optical band gap at 1.5 eV. The first resonance peak in the imaginary portion of the complex dielectric constant was at 1.9 eV.

The influence of growth temperature from 170 to 730 deg C on the characteristics of as-deposited 1000 angstrom thick Ta2O5 films was investigated. The layers were grown through the evaporation of tantalum metal on silicon exposed to a flux of oxygen radicals. Films grown at or below 400 deg C were found to be deposited in an amorphous state. The layers grown at 520 deg C were found to be in a nanocrystalline state with no apparent grain boundaries while the films grown at 650 deg C had distinct grain boundary formation in the beta-phase modification of Ta2O5.

Research was conducted to characterize Sr-deficient and stoichiometric epitaxial (001) SrTiO3 films, deposited on (110)(sub rhombohedral) LaAlO3 substrates by x-ray diffraction and a high-resolution transmission electron microscopy. Objective of the study was to determine the reason for the significance of a heat treatment after deposition, tetragonal distortion and the influence of strain relaxation. Results indicate that the tetragonal distortion caused by the mismatch strain was concentrated to a narrow region closest to the film/substrate interface.

Investigation of tin oxide films doped with oxygen vacancies, molybdenum, tin or fluorine reveals that those films doped with tin or flourine or both possess the lowest value of resistivity and very high luminous transmittance. These films also have a low luminous absorptance value and infrared reflectance in the range of 70% to 90%. Hall effect analysis performed on these films indicates the existence of n-type conduction with very high electron densities. The properties of these films are permanent and are not affected by the passage of time.

The precursor oxide phases of pulsed laser deposited-YBCO films grown on (100)-oriented SrTiO3 substrates intermix to form a novel epitaxial solid-phase film. Epitaxial nucleation of the YBCO layers by the substrate interface is essential for solid-phase film formation. In situ resistance observations of the YBCO growth phase showed that interdiffusion occurs very quickly and immediately after production of ablated products from the initial precursor oxide layer.

In-plane orientation of the c-axis-oriented YBa2Cu3O(7-x) (YBCO) thin films prepared on (001) yttria-stabilized ZrO2(YSZ) substrates are sensitive to deposition properties resulting in mixed orientations. A dominant (110)(sub YBCO)/(110)(sub YSZ) orientation is detected at a deposition temperature of 770 degrees Celsius. The film microstructure on stepped substrate surfaces influence microwave surface resistance and contain superconducting properties.

Laser deposition methods yield YBa2Cu3O(7-X)/insulator/YBa2Cu3O(7-x) trilayers having one PrGaO3 layer and an SrTiO3 (STO)/PGO multilayer. Pinholes in PGO layers produce superconducting microshorts, and are eliminated by introducing thin STO films as buffer layers in the PGO.

The modified off-axis sputtering technique with high deposition rates is used to obtain high quality epitaxial YBa2Cu3O(sub 7-delta). The target-to-substrate separation influenced the deposition rate and film quality. Epitaxial YBCO/NdGaO3(NGO)/YBCO trilayers were grown onto SrTiO3, Y-ZrO2 and LaAl/O3 substrates by direct current and radio frequency sputtering. The top YBCO layers grew c axis oriented unaffected by the two epitaxial orientation of the NGO and the orientation relationships between YBCO/NGO were the same.

Y1Ba2Cu3Ox (YBCO) and Y-ZrO2 (YSZ) films were grown by pulsed layer deposition technique on sapphire substrates. It was observed that the c-axis oriented YBCO grows on amorphous YSZ at an optimal thickness of YSZ. An buffer layer of nine nanometers produced a Tc of 89 Kelvin which reflect the strong correlation of the properties of YBCO and the thickness of the buffer layer. The experiment further developed a model which showed the film growth process.

Atomic force microscopy and transmission electron microscopy facilitated the study of the initial growth stages of YBa2Cu3O(7-delta) (YBCO) films that were grown on (001) Y-ZrO2 substrates using pulsed laser deposition. Initial growth stages include the formation of large CuO particles and a YBCO layer that was one unit cell thick.

A type of scanning microscope is described that has worked by directed imaging the electron field-emission sites on a nanotip. The advantages of the low energy, bright-beam electron microscope with atomic resolution are described and they are used for sequencing the human genome from a single strand DNA and for identifying atomic species directly from the elastic scattering of electrons.

Current and voltage noise measurements are carried out on nanaparticle WO3. Results on the thinnest films show that noise measurements can be used for quality assessment of nanocrystalline insulating films.

The analysis of isothermal grain growth in thin nanocrystalline gold films, which was prepared by an advanced gas deposition method, using in situ electrical transport measurements is reported. The samples with low grain boundary transmission coefficients showed an increased thermal stability with negligible grain growth upon treatments in vacuum at 773 K for 2 hours.