Materials Chemistry and Physics 

About: Materials Chemistry and Physics is an academic journal published by Elsevier BV. The journal publishes majorly in the area(s): Materials science & Thin film. It has an ISSN identifier of 0254-0584. Over the lifetime, 21058 publications have been published receiving 462536 citations.

Prediction of high-entropy stabilized solid-solution in multi-component alloys

Abstract: Phase formation for the multi-component alloys has been predicted by calculating parameter Ω and δ for typical multi-component alloys reported. Here, Ω is defined as a parameter of the entropy of mixing timing the average melting temperature of the elements over the enthalpy of mixing, δ is the mean square deviation of the atomic size of elements. It shows that the high-entropy (HE) stabilized solid-solution is located at Ω ≥ 1.1 and δ ≤ 6.6%.

Characterization of amorphous and nanocrystalline carbon films

Abstract: Amorphous and nanocrystalline carbon films possess special chemical and physical properties such as high chemical inertness, diamond-like properties, and favorable tribological proprieties. The materials usually consist of graphite and diamond microstructures and thus possess properties that lie between the two. Amorphous and nanocrystalline carbon films can exist in different kinds of matrices and are usually doped with a large amount of hydrogen. Thus, carbon films can be classified as polymer-like, diamond-like, or graphite-like based on the main binding framework. In order to characterize the structure, either direct bonding characterization methods or the indirect bonding characterization methods are employed. Examples of techniques utilized to identify the chemical bonds and microstructure of amorphous and nanocrystalline carbon films include optical characterization methods such as Raman spectroscopy, Ultra-violet (UV) Raman spectroscopy, and infrared spectroscopy, electron spectroscopic and microscopic methods such as scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy, transmission electron microscopy, and electron energy loss spectroscopy, surface morphology characterization techniques such as scanning probe microscopy (SPM) as well as other characterization methods such as X-ray reflectivity and nuclear magnetic resonance. In this review, the structures of various types of amorphous carbon films and common characterization techniques are described.

Bandgap studies on anatase titanium dioxide nanoparticles

Abstract: Titanium dioxide, predominantly in the anatase phase with an average grain size of 5–10 nm, has been synthesized by the hydrazine method. These nanocrystalline particles show a blue shift in the absorption edge of the diffuse reflectance ultraviolet spectrum of about 10 nm compared to that of commercially available titania. Synthesized samples were characterized by X-ray diffraction and transmission electron microscopy for their structural properties and UV-Vis absorption spectroscopy for the bandgap studies. The absorption spectra show a linear fit for the direct transition. The optical and electrical properties of the samples have been studied and the Arrhenius plots of electrical conductivity both for the as-prepared anatase TiO 2 and the one subsequently reduced in hydrogen atmosphere at 673 K show a distinct difference in the activation energy. The hydrogen-annealed sample shows a typical semiconducting behavior whereas the as-prepared sample indicates a phonon contribution to the conductivity around 300 K.

Electrochromic materials and devices: present and future

Abstract: The increase in the interaction between man and machine has made display devices indispensable for visual communication. The information which is to be communicated from a machine can be often in the form of color images. Electrochromic display device (ECD) is one of the most powerful candidate for this purpose and has various merits such as multicolor, high contrast, optical memory, and no visual dependence on viewing angle. A large number of electrochromic materials are available from almost all branches of synthetic chemistry. In this review, we have tried to describe the fundamentals of such electrochromic materials and their use in EDDs. The most important examples from major classes of electrochromic materials namely transition metal oxides, Prussian blue, phthalocyanines, viologens, fullerenes, dyes and conducting polymers (including gels) are described. Examples of their use in both prototype and commercial electrochromic devices are given.

Chemical deposition method for metal chalcogenide thin films

Abstract: Metal chalcogenide thin films preparation by chemical methods are currently attracting considerable attention as it is relatively inexpensive, simple and convenient for large area deposition. A variety of substrates such as insulators, semiconductors or metals can be used since these are low temperature processes which avoid oxidation and corrosion of substrate. These are slow processes which facilitates better orientation of crystallites with improved grain structure. Depending upon deposition conditions, film growth can take place by ion-by-ion condensation of the materials on the substrates or by adsorption of colloidal particles from the solution on the substrate. Using these methods, thin films of group II–VI, V–VI, III–VI etc. have been deposited. Solar selective coatings, solar control, photoconductors, solid state and photoelectrochemical solar cells, optical imaging, hologram recording, optical mass memories etc. are some of the applications of metal chalcogenide films. In the present review article, we have described in detail, chemical bath deposition method of metal chalcogenide thin films, it is capable of yielding good quality thin films. Their preparative parameters, structural, optical, electrical properties etc. are described. Theoretical background necessary for the chemical deposition of thin films is also discussed.