Characterization Of Inorganic Materials Research Articles

Application of Direct Methods to Inorganic Materials Characterization

Although in the last years most attention has been paid to the development of direct methods (DM) in the macromolecular field, DM also play an important role in the characterization of inorganic materials. Very challenging is nowadays the structure solution of increasingly small crystals. Here the difficulty is not associated with the large number of atoms but with experimental limitations which may affect the data accuracy and the completeness of the data sets. It is obvious that DM have to adapt to this emerging scientific need. Particularly interesting has been the evolution of Patterson-function DM to cope with these objectives. The initial formulation based on the explicit use of triple-phase sums was modified to permit the calculation with Fourier transforms thus resulting in the more simple and accurate S-FFT algorithm [1]. Thanks to the resulting increased simplicity, this algorithm could be easily adapted to the treatment of powder diffraction data of complex inorganic materials [2]. The practical application of this algorithm is analyzed by using data of some synthetic and natural materials. Recently, the possibility of collecting good quality 3D intensity data from very small nanovolumes by new sophisticated electron diffraction (ED) techniques has become a reality. However, these data sets are often incomplete and, in addition, the intensities are not completely kinematical. The processing of these data sets represents a new challenge for DM. To this purpose a new (even more simple) Patterson-function DM (called delta-recycling) has been developed and tested on precession ED data from inorganic materials with variable degree of difficulty [3]. Phasing with delta-recycling proves to be highly efficient and from the interpretation of the results important practical conclusions can be drawn.

Sol–Gel Synthesis of a Biotemplated Inorganic Photocatalyst: A Simple Experiment for Introducing Undergraduate Students to Materials Chemistry

As part of a laboratory course, undergraduate students were asked to use baker’s yeast cells as biotemplate in preparing TiO2 powders and to test the photocatalytic activity of the resulting materials. This laboratory experience, selected because of the important environmental implications of soft chemistry and photocatalysis, provides an opportunity to teach valuable laboratory skills and to introduce students to the synthesis, isolation, and characterization of inorganic materials. This laboratory activity is adaptable to a range of educational levels and to various instrumental techniques.

Advanced experimental facilities for SHS Studies and physico-chemical characterization of inorganic materials: An autoreview

Overviewed are new experimental methods for investigating the processes of phase formation during SHS. The first experiments using penetrating synchrotron radiation and energy dispersive detectors for different classes of complex inorganic materials were carried out in ESRF (Grenoble, France), LURE (Orsay, France) and Daresbury (UK). A new and very sensitive thermal imaging method (Thermal Imaging Technique, TIT) is based on continuous registration of the whole combustion process by using a highly sensitive IR camera and software developed by MIKRON Instruments Co. (USA) was also used for precise registration of combustion parameters. SHS was performed on different types of pure on doped complex inorganic materials in pellet and powder form in a range of dc magnetic field induction up to 20 T and electrical field strength up to ±220 kV/m. The dc magnetic field was applied during the reaction, supplied either by permanent magnet (transverse, 1.1 T) or by an electromagnet (longitudinal, up to 20 T). The dc electrical field was applied along direction of the combustion wave propagation. The combined processes of SHS and SLS (Selective Laser Sintering) of 3D articles for different powdered compositions was realized with optimal parameters of laser irradiation, under what SHS reactions proceeded in controlled regime.

Book Review of Inorganic Materials Synthesis and Fabrication

Inorganic Materials Synthesis and Fabrication provides an introduction to all that is solid-state inorganic materials. From chapters on crystallographic factors and chemical energetics to comprehensive chapters on synthetic methods in the gas, liquid, and solid states, to final chapters covering synthesis and fabrication techniques of nanomaterials, this text covers it all. The authors start with a fast-paced chapter on the importance of structure in determining the bulk properties of a solid and the use of crystallography in determining solid-state structures. The second chapter is a whirlwind discussion of chemical energetics with sections on equilibrium and nonequilibrium thermodynamics, bulk and surface energy considerations, and phase transformation kinetics. While well written, these two chapters are not for the novice. It is assumed that the reader has considerable familiarity with physical methods and chemical principles. The authors express their philosophy of the first two chapters best in an excerpt from a section on phase diagrams: “The following brief introduction is meant merely to encourage the reader to refer to any one of several available texts that offer r2010 American a range from introductory to comprehensive coverage of all aspects of phase equilibria”. The real gems of the text are the middle three chapters on solid-vapor reactions, solid-liquid reactions, and solid-solid reactions, respectively. If you are new to inorganic materials synthesis, you will find these chapters helpful in guiding your research endeavors. The physical and chemical considerations involved in each type of synthetic method are covered in sufficient detail to give the reader an appreciation of the overall picture. Each chapter begins with a discussion of the fundamentals of the synthetic method under consideration followed by examples to illustrate key points. The authors do a good job defining terms and using figures to clarify synthetic techniques. The tour concludes with chapters on nanomaterials synthesis and materials fabrication. The nanomaterials chapter succinctly covers both top-down physical fabrication and bottom-up chemical synthesis methodologies for nanomaterials. The final chapter provides an introduction to common fabrication techniques and an explanation of how the method of fabrication can influence the performance and suitability of a material for a specific application. Overall, the text is well written. A unique feature is the inclusion of biographical sketches of individuals who have made important contributions to the synthesis and characterization of inorganic materials. The sketches are brief, usually less than one page, but provide an often-overlooked part of science and discovery: the human aspect. Each chapter ends with an extensive list of references for the reader who seeks further clarification on a topic. Using the text as a supplement in a graduate-level special topics course on inorganic materials is conceivable. A more likely use is as a reference for the professional chemist, physicist, material scientist, or engineer interested in starting research projects in the field of inorganic solid-state materials.

Inorganic Hybrid Materials with Encapsulated Polyoxometalates

This review describes the synthesis and characterization of inorganic materials containing polyoxometalates encapsulated in oxide matrices. Examples illustrating key aspects in terms of synthesis and applications are presented according to the nature of the final hybrid material: those based on non-structured silicas, on mesostructured silicas, on macrostructured silicas and on other oxides. In each part, key points of the synthetic protocols are highlighted and structural features and properties of the resultant hybrid nanocomposites are discussed.

Laser ablation and static secondary ion mass spectrometry capabilities in the characterization of inorganic materials

Recently, mass spectrometry techniques such as laser ablation and static secondary ion mass spectrometry (LA-MS and s-SIMS, respectively) have been successfully applied to the characterization of inorganic compounds in solid state phase: s-SIMS is known as a surface analytical technique whereas LA-MS involves atoms in a greater thickness (bulk). In the case of s-SIMS, the direct ejection of ions from the surface upon primary ion sputtering for ion fluence down to 10 13 ions/cm 2, leads to a simple and direct diagnostic by comparing the spectra to databases. On the opposite, characterization of inorganic compounds by means of LA-MS is not immediate due to the most detected ions are issued from complex gas phase reactions. This feature can be successfully applied to investigate matter transfer processes occurring during pulsed-laser deposition (PLD) experiments. By the mean of a systematic and comparative study of LA-MS and s-SIMS spectra for binary (Cu–O) or ternary (Fe–Cr–O) oxide systems, we demonstrate that both techniques are complementary to each other in the field of material science.

Characterization of inorganic materials with photoacoustic spectrophotometry

Abstract A photoacoustic spectrometer is described which has been constructed to measure the spectra of photovoltaic or other solid materials in the ultraviolet (UV), visible and near infrared regions. The range of this photoacoustic spectrometer is from 0.3 to 1.8 μm. The spectrometer was used to characterize the optical properties of polycrystalline and single phase p-CuInSe2 thin films which were grown by selenization of sputtered Cu/In multilayer at a temperature of 500°C. The films showed a three-fold optical structure with three high energy transitions, which is the characteristic behavior of the material. The photoacoustic spectrum is reported and discussed.

Applications of Thermal Analysis to the Study of Inorganic Materials

Three examples are selected fron the author's current work to illustrate the important role that thermoanalytical techniques play in the characterization of inorganic materials and their processing. The first example deals with the crystal growth, phase equilibria, and defect structure of lithium niobate. This is a prominent material used in electro-optical devices. The second example deals with the relatively new electrooptical material, KTiOAsO 4. Its thermal stability and expansion will be discussed. Some information is also included on the ferroelectric transition temperature and the melting point. The final topic is an application of thermomagnetometry to study the thermal decomposition of solid solutions and physically mixed oxalates of nickel and cobalt in an inert atmosphere. The magnetic transition temperature is used to establish whether the metal initially formed is an alloy or mixture of pure metals.