Nano-crystalline

Microwave power and its effect on the electrode/electrolyte interface, 439 Microwave region, Hall experiments, 453 Microwave spectroscopy, intensity modulated photo currents, 508 Microwave transients for nano crystalline desensitized cells, 514 Microwave transmission, as a function of magnetic field, 515 Minority carriers... 

Jang, Y.J., Simer, C. and Ohm, T. (2006) Comparison of zinc oxide nanoparticles and its nano-crystalline particles on the photocatalytic degradation of methylene blue. Materials Research Bulletin, 41,67-77. 

Conversion and Storage of Solar Energy using Dye-sensitized Nano crystalline Ti02 Cells 745... 

Pressure-induced amorphization of solids has received considerable attention recently in physical and material sciences, although the first reports of the phenomenon appeared in 1963 in the geophysical literature (actually amorphization on reducing the pressure [18]). During isothermal or near isothermal compression, some solids, instead of undergoing an equilibrium transition to a more stable high-pressure polymorph, become amorphous. This is known as pressure-induced amorphization. In some systems the transition is sharp and mimics a first-order phase transition, and a discontinuous drop in the volume of the substance is observed. Occasionally it is strictly not an amorphous phase that is formed, but rather a highly disordered denser nano-crystalline solid. Here we are concerned with the situation where a true amorphous solid is formed. 

SubramaniaA, SaradhaT, and Muzhumathi S. Synthesis of nano-crystalline (Ba05Sr05) Co08Fe0 203 g cathode material by a novel sol-gel thermolysis process for IT-SOFCs. J. Power Sources 2007 165 728-732. 

The model analytes, which were used to show the sensor performance of the microsystems include carbon monoxide, CO, and methane, CH4. The sensor microsystems were designed for practical applications, such as environmental monitoring, industrial safety applications or household surveillance, which implies that oxygen and water vapors are present under normal operating conditions. In the following, a brief overview of the relevant gas sensor mechanisms focused on nano crystalline tin-oxide thick-film layers will be given. 

Figure 2.3 shows a schematic view of the nano crystalline sensor material. It consists of single-crystalline tin-oxide grains with a typical size of 10 nm and a narrow size distribution [68]. The grains are in loose contact. The lower graph in Fig. 2.3 schematically represents the conduction band of the layer. 

The doping-induced effects on the gas sensing performance of nano crystalline tin oxide include, first and foremost, a conductivity decrease in clean air by one to three orders of magnitudes, and, secondly, a shift of the optimal sensor working temperature from higher to lower temperatures. 

The first device is a circular microhotplate (Sect. 4.1). One important guideline was to implement the microhotplate in CMOS technology with a minimum of post-CMOS micromachining steps. Additionally the hotplate had to be optimized for drop-coating with nano crystalline tin-oxide layers. This microhotplate was cointegrated with circuitry, and the respective monolithic sensor system will be discussed in Sect. 5.1. 

Fig. 4.10. Measured relative temperature differences between the temperatiu e sensors T2 to and T. The microhotplate was coated with a nano-crystalline Sn02 droplet...

As an example, result from a test sample is presented in Figure 6. A nano-crystalline thin film sample was prepared by vacuum evaporation of 100 A NiO and 100 A Al. The thicknesses were controlled by quartz thickness measurement. The proportion of phases was also checked by EDS. TEM BF and DF pictures show that the grain size of NiO is around 4 nm. 

Phthalocyanines exhibit high polymorphism, as well [7]. They are insoluble nano crystalline materials, which produce poor x-ray powder diagrams with high preferred orientation and have been intensely investigated by electron microscopy and diffraction [8]. From copper phthalocyanine (CuPc) (Fig.2) nine polymorphs (a, P, y, 5, s, n, p, (, a and R) are known, but only the most stable P phase could be solved by single crystal x-ray diffraction [9] (P2i/c a=14.628 A, b= 4.790 A, c= 19.07 A, b=120.93°). 

Kristiakova, K., Svec, P. Deanko, M. (2004) Cluster structure and thermodynamics of formation of (nano)crystalline phases in disordered metastable metallic systems. Mat. Sci. Eng. A 375-377,136. 

Vaughan, D.E.W. and Strohmeier, K.G. (1994) Process for preparing LTL nano-crystalline zeolite compositions. US Patent 5,318,766. 

OXIDE SEMICONDUCTORS NANO-CRYSTALLINE, TUBULAR AND POROUS SYSTEMS... 

Oxide Semiconductors Nano-Crystalline, Tubular and Porous Systems... 

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