Morphology crystal size

Morphologies (crystal size and shape, aggregates, mesopores, Rabo s contiguous crystal growth, etc.)... 

To summarize, the electrochemical performance of these inorganic oxides, characterized by their reversible capacity and cycling behavior, is mainly dependent on their morphology, crystal size, and crystallinity, and can be improved by optimization. Their main problem is the voltage hysteresis during lithium insertion and extraction or removal. 

Finally, the nature of the crystalline microstmcture, ie, crystal size and morphology and the textural relationship among the crystals and glass, is the key to many mechanical and optical properties, including transparency/opacity, strength and fracture toughness, and machinabiUty. These microstmctures can be quite complex and often are distinct from conventional ceramic microstmctures (6). 

Optimizing the Cr layer also controls the crystal size and morphology. It was reported in 1986 (89,90) that the Cr underlayer thickness has a great influence on the coercivity of the Co—Ni—Cr layer. In most of the Hterature it can be found that with increasing Cr thickness the increases. Under ideal conditions and the right material combinations coercivities above 240 kA/m have been prepared. 

Population balances and crystallization kinetics may be used to relate process variables to the crystal size distribution produced by the crystallizer. Such balances are coupled to the more familiar balances on mass and energy. It is assumed that the population distribution is a continuous function and that crystal size, surface area, and volume can be described by a characteristic dimension T. Area and volume shape factors are assumed to be constant, which is to say that the morphology of the crystal does not change with size. 

Thin films of metals, alloys and compounds of a few micrometres diickness, which play an important part in microelectronics, can be prepared by die condensation of atomic species on an inert substrate from a gaseous phase. The source of die atoms is, in die simplest circumstances, a sample of die collision-free evaporated beam originating from an elemental substance, or a number of elementary substances, which is formed in vacuum. The condensing surface is selected and held at a pre-determined temperature, so as to affect die crystallographic form of die condensate. If diis surface is at room teiiiperamre, a polycrystalline film is usually formed. As die temperature of die surface is increased die deposit crystal size increases, and can be made practically monocrystalline at elevated temperatures. The degree of crystallinity which has been achieved can be determined by electron diffraction, while odier properties such as surface morphology and dislocation sttiicmre can be established by electron microscopy. 

Phase purity and crystallinity of the obtained zeolites were characterized using XRD (Siemens 5005). The morphology and crystal size were determined using SEM (Philips... 

The given discussion shows that rather universal and simple classification of porous materials equivalent to classification of crystals is absent. However, one can consider a system of interrelating classifications that take into account order, morphology and sizes at different hierarchical levels, degrees of integrity, structure, heterogeneity of a various type, etc. Such a systematic approach can be used as well for adequate modeling of various hierarchical levels of a porous material structure. 

Microscopy is used to identify crystal morphology and size, and to assess physical form issues like agglomeration and solvent occlusion. It can be used to observe polymorphic transformations in real time with the addition of a hot stage fitting. 

Given the complex nature of the crystal structure and small crystal size with an anisotropic morphology of UZM-5, the normal X-ray diffraction patterns were not sufficient to deduce an unambiguous structure. Thus a multi-technique approach was required to successfully solve the structure, to explain the adsorption properties and by analogy to the structure of other zeolites in order to assess potential applications. 

I 4 Crystal morphology and size Tab. 4.2 Habits of iron oxides... 

---