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Abstract Bismuth magnesium niobate (Bi 3/2 MgNb 3/2 O 7 , BMN) thin films were prepared on bare SiO 2 /HR-Si and Pt/TiO 2 /SiO 2 /HR-Si substrates by using sol-gel spin coating technique followed by rapid thermal annealing process. The influence of the interface on crystalline structure and tunable dielectric properties of the two types of BMN films were investigated. It was found that the BMN films prepared on SiO 2 /Si substrate with a BMN/SiO 2 interface structure had higher orientation and better crystallinity. The deposited BMN thin films with a BMN/SiO 2 interface structure exhibited superior tunability of 52.5%, while it showed a relative small tunability value of the film with BMN/Pt interface structure. It suggests that the interface state between the films and substrates, electric field distribution, and orientation degree are responsible for the impacts on the microstructure and tunable dielectric properties of the BMN thin films. [ABSTRACT FROM AUTHOR]

The method of X-ray standing wave-structure-sensitive spectroscopy of condensed matter surface and thin films-is described. The theoretical basis of the method and the possibilities of its application for investigation of crystalline and organic nanostructures are considered. [ABSTRACT FROM AUTHOR]

The surface work function (WF) and substrate temperature dependence of the NaCl thin-film growth on Ag(001) have been studied by noncontact atomic force microscopy and Kelvin probe force microscopy. In the sub-monolayer range, the NaCl film is composed of large crystalline islands, which decrease in density and increase in size with increasing temperature during deposition. Each island is composed of a large base island 2 monolayers (ML) thick (for T > 343 K), which collects impinging NaCl molecules that form adislands on top. Kelvin probe force microscopy (KPFM) measurements show a reduction of the silver WF by Δφ = φAg -φNaCl/Ag = 0.69±0.03 eV with no dependence on the film thickness (1-6 ML), in agreement with recent theoretical calculations. The previously observed nanometer-sized moiré pattern on islands that are 45° rotated with respect to the silver lattice could be observed in the scanning tunneling microscopy mode. However, no contrast could be obtained in KPFM images. [ABSTRACT FROM AUTHOR]

Nanocrystalline CdO thin films were prepared by sol-gel dip-coating method using a different solution. The as-deposited films were subjected to drying temperature of 120° in air. The prepared films were annealed in different temperatures of 200, 300 and 400 °C. The characterization of samples was carried out by X-ray diffraction, scanning electron microscopy and UV-VIS spectroscopy. Results show that the samples are polycrystalline in nature and the crystallinity of the films improves with temperature. The average grain size is in the range of 19-34 nm. It was observed that the optical parameters of the films were affected by annealing temperature. [ABSTRACT FROM AUTHOR]

Abstract: The influences of solvent solubility and solution aging on the crystallization of poly(3-hexylthiophene) (P3HT) films were investigated. The solubility difference rather than the evaporation rate of solvent determined the final morphology and crystallinity of film. Marginal solvents (toluene and xylene) with large solubility difference caused crystalline aggregations in solutions during the aging process and then densely stacked network-like structures in solid films. Few crystalline aggregates in good solvent chloroform resulted in a thin layer of fibrillar crystals on the substrate, while dot-like crystals deposited on the substrate from good solvent chlorobenzene since no crystalline aggregates formed in the solution. [Copyright &y& Elsevier]

Abstract: Hierarchically structured CaCO3 films were synthesized at atmospheric conditions (room temperature and 1atm) without the use of templates or amphiphilic molecules in this process. The resulting CaCO3 film was formed by self-organization between Ca(OH)2 and aqueous CO2. The building blocks of the CaCO3 film were thought to be CaCO3 primary nanoparticles that aligned to build higher level structures with greater size, called mesocrystals, depending on the additives. The soluble additives played a key role in the control of the morphology, crystallinity, and polymorphism of the CaCO3 film, and the effects strongly depended on the type of additive and their concentrations. The additives used in this study decreased the crystallinity of CaCO3 (calcite) film in the order of glucose>aspartic acid>serine in a manner inversely proportional to the concentration of the additives. In addition, Mg2+, K+, and Na+ ion additives led to the formation of an aragonite phase, the proportion of which increased with the concentration of ions. The threshold concentrations of these ions for the formation of the aragonite phase in CaCO3 film were found to be in the order of Na+ >K+ >Mg2+. [ABSTRACT FROM AUTHOR]

In this work we have synthesized FePtP films using sodium hypophosphite as source material for phosphorous. The surface morphology, crystalline structure, grain size and magnetic properties of the plated films prepared at various current densities, bath temperature and concentration of phosphorous source material (NaH2PO2) have been compared. The results shows that the structural & magnetic properties of this thin film depends on the phosphorus content in the film. When the bath temperature increases the phosphorus content decreases & hence coercivity increases. Also coercivity increases after annealing. Reasons for variation in magnetic properties and structural characteristics were discussed. [ABSTRACT FROM AUTHOR]

Phase change materials (PCMs) can exist in at least two different phases (an amorphous and one or more crystalline phases), and they can be switched repeatedly between these phases. The different phases have distinctly different physical properties such as electrical conductivity, optical reflectivity, mass density or thermal conductivity. These differences and the repeatability of the switching give these materials the ability to store information. Rewritable compact discs, digital versatile discs, and Blu-ray™ discs store information in thin films of PCMs, using the difference in reflectivity between the phases as the storage mechanism. A novel solid-state memory technology that applies the difference in electrical resistivity is currently being developed, and possible future applications include reconfigurable logic. This article reviews the unique set of properties of PCMs and their current and future applications. [ABSTRACT FROM AUTHOR]

Polycrystalline silicon obtained by the crystallization of thin amorphous silicon films has been an important material for microelectronics technology during the last decades. Many properties are improved in crystallized amorphous silicon compared to the as-deposited polysilicon such as larger grain size, smoother surface, and higher-carrier mobility. In this work, the crystallization of amorphous silicon is investigated by combining transmission electron microscopy (TEM) observations and molecular dynamics calculations. TEM observations on a series of specimens have shown that the majority of the silicon grains are oriented with a $$ {\left\langle {110} \right\rangle} $$ zone axis normal to the surface. In order to understand the crystallization mechanism molecular dynamic simulations were performed. It is found that the $$ {\left\langle {110} \right\rangle} $$ c/amorphous interface exhibits the lowest reduced interfacial energy density while the $$ {\left\langle {111} \right\rangle} $$ c/amorphous has the lowest reduced energy differences per unit interfacial area. The most energetically unfavorable interface is $$ {\left\langle {001} \right\rangle} $$ c/amorphous. [ABSTRACT FROM AUTHOR]

It was found that prolonged high-energy ball-milling of Hilgenstokite (tetracalcium phosphate, TTCP) resulted in a decrease in both particle and crystallite size, leading to a mechanical activation of the compound. This mechanically activated material demonstrated a high reactivity such that, in contrast to highly crystalline TTCP, a setting reaction with water to nanocrystalline hydroxyapatite (HA) and Ca(OH)2 could be achieved at 37°C. However, crystalline TTCP is practically unreactive at physiologic temperatures because of the formation of a thin HA layer on the particle surface preventing further reaction. [ABSTRACT FROM AUTHOR]

Provides information on a study which created a unique type of two dimensional (2D) isotropic media with crystalline texture in the magnetic layer. Intrinsic signal-to-noise ratio, cross track noise and texture-induced modulation noise; Thin-film media demanded by increasing linear and track density; Comparison of 2D-isotropic media with oriented and three dimensional random isotropic media.

The origins of spin exchange in crystalline thin films of Copper Octabutoxy Phthalocyanine (Cu-OBPc) are investigated using Magnetic Circular Dichroism (MCD) spectroscopy. These studies are made possible by a solution deposition technique which produces highly ordered films with macroscopic grain sizes suitable for optical studies. For temperatures lower than 2 K, the contribution of a specific state in the valence band manifold originating from the hybridized lone pair in nitrogen orbitals of the Phthalocyanine ring, bears the Brillouin-like signature of an exchange interaction with the localized d-shell Cu spins. A comprehensive MCD spectral analysis coupled with a molecular field model of a σπ − d exchange analogous to sp-d interactions in Diluted Magnetic Semiconductors (DMS) renders an enhanced Zeeman splitting and a modified g-factor of −4 for the electrons that mediate the interaction. These studies define an experimental tool for identifying electronic states involved in spin-dependent exchange interactions in organic materials. [ABSTRACT FROM AUTHOR]