Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications

Amorphous alloys were first developed over 40 years ago and found applications as magnetic core or reinforcement added to other materials. The scope of applications is limited due to the small thickness in the region of only tens of microns. The research effort in the past two decades, mainly pioneered by a Japanese- and a US-group of scientists, has substantially relaxed this size constrain. Some bulk metallic glasses can have tensile strength up to 3000 MPa with good corrosion resistance, reasonable toughness, low internal friction and good processability. Bulk metallic glasses are now being used in consumer electronic industries, sporting goods industries, etc. In this paper, the authors reviewed the recent development of new alloy systems of bulk metallic glasses. The properties and processing technologies relevant to the industrial applications of these alloys are also discussed here. The behaviors of bulk metallic glasses under extreme conditions such as high pressure and low temperature are especially addressed in this review. In order that the scope of applications can be broadened, the understanding of the glass-forming criteria is important for the design of new alloy systems and also the processing techniques.

https://www.tcd.ie/Physics/people/Graham.Cross/SF%20Poster%202011/Shek-MaterSciEng04-Bulk%20Metallic%20Glasses.pdf

Bulk metallic glasses

Phase-change materials are some of the most promising materials for data-storage applications. They are already used in rewriteable optical data storage and offer great potential as an emerging non-volatile electronic memory. This review looks at the unique property combination that characterizes phase-change materials. The crystalline state often shows an octahedral-like atomic arrangement, frequently accompanied by pronounced lattice distortions and huge vacancy concentrations. This can be attributed to the chemical bonding in phase-change alloys, which is promoted by p-orbitals. From this insight, phase-change alloys with desired properties can be designed. This is demonstrated for the optical properties of phase-change alloys, in particular the contrast between the amorphous and crystalline states. The origin of the fast crystallization kinetics is also discussed.

Phase-change materials for rewriteable data storage

Recent experiments, advances in theory, and analogies to other complex systems such as glasses and spin glasses yield insight into protein dynamics. The basis of the understanding is the observation that the energy landscape is complex: Proteins can assume a large number of nearly isoenergetic conformations (conformational substates). The concepts that emerge from studies of the conformational substates and the motions between them permit a quantitative discussion of one simple reaction, the binding of small ligands such as carbon monoxide to myoglobin.

https://science.sciencemag.org/content/sci/254/5038/1598.full.pdf

The energy landscapes and motions of proteins.

Preface Acknowledgements Notation Part I. Overview and Background Topics: 1. Introduction 2. Overview 3. Theoretical background 4. Periodic solids and electron bands 5. Uniform electron gas and simple metals Part II. Density Functional Theory: 6. Density functional theory: foundations 7. The Kohn-Sham ansatz 8. Functionals for exchange and correlation 9. Solving the Kohn-Sham equations Part III. Important Preliminaries on Atoms: 10. Electronic structure of atoms 11. Pseudopotentials Part IV. Determination of Electronic Structure, The Three Basic Methods: 12. Plane waves and grids: basics 13. Plane waves and grids: full calculations 14. Localized orbitals: tight binding 15. Localized orbitals: full calculations 16. Augmented functions: APW, KKR, MTO 17. Augmented functions: linear methods Part V. Predicting Properties of Matter from Electronic Structure - Recent Developments: 18. Quantum molecular dynamics (QMD) 19. Response functions: photons, magnons ... 20. Excitation spectra and optical properties 21. Wannier functions 22. Polarization, localization and Berry's phases 23. Locality and linear scaling O (N) methods 24. Where to find more Appendixes References Index.

Electronic Structure: Basic Theory and Practical Methods

The Formation of Amorphous Solids Amorphous Morphology: The Geometry and Topology of Disorder Chalcogenide Glasses and Organic Polymers The Percolation Model Localization Delocalization Transitions Optical and Electrical Properties Index.

http://www.gbv.de/dms/ilmenau/toc/024142883.PDF

The physics of amorphous solids

Critical Density in Percolation Processes

Polarization-dependent far-infrared reflectivity measurements were carried out on single crystals of anatase ${\mathrm{TiO}}_{2}$ . The results were analyzed to yield the dielectric dispersion properties of anatase in the lattice fundamentals regime. The frequencies (in ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ ) of the transverse optical (TO) and longitudinal optical (LO) zone-center phonons were determined to be 367(755) for the TO (LO) of the ${\mathrm{A}}_{2\mathrm{u}}$ mode, 262(366) and 435(876) for the ${\mathrm{E}}_{\mathrm{u}}$ modes. The large TO-LO splittings were used to estimate effective charges.

/pdf/infrared-reflectivity-and-lattice-fundamentals-in-anatase-59fk9e23fv.pdf

Infrared reflectivity and lattice fundamentals in anatase TiO 2 s

The optical absorption edge of brookite TiO2

Zone-center optical phonons in the layer crystals ${\mathrm{As}}_{2}$${\mathrm{S}}_{3}$ and ${\mathrm{As}}_{2}$${\mathrm{Se}}_{3}$ have been investigated in far-infrared reflectivity and transmission measurements (for both polarizations in the layer plane), and in Raman scattering. About a dozen infrared-active fundamentals were found for each crystal, along with a like number of Raman-active modes. Polariton dispersion curves, as well as dielectric dispersion properties and TO and LO frequencies, have been derived from oscillator analyses of the complex reststrahlen spectra. Grouptheoretical analysis of the diperiodic symmetry of the individual layer, as well as of the triperiodic symmetry of the crystal, reveals that the two symmetries predict experimentally distinguishable lattice optical properties. Our experiments demonstrate the dominance of the layer symmetry. By means of the combination of Raman and infrared results, we have been able to observe effects of the weak interlayer interactions; vibrational Davydov splittings have been resolved. A surprisingly simple scaling relation is found to connect the lattice spectra of the two crystals, and these spectra have also been compared to those of the amorphous forms.

Richard Zallen

Papers

The physics of amorphous solids

Critical Density in Percolation Processes

Infrared reflectivity and lattice fundamentals in anatase TiO 2 s

The optical absorption edge of brookite TiO2

Lattice Vibrations and Interlayer Interactions in Crystalline As 2 S 3 and As 2 Se 3