Nanowire description

After an introduction to methods of electronic structure calculations, we review how recent trends translate into the description of magnetic nanostructures. Among the considered structures are nanowires, small particles, surfaces and interfaces, and multilayers, and emphasis is on magnetic properties such as moment and magnetization, interatomic exchange, and anisotropy. 

The more sophisticated potentials used in the nanowire study point to an important consideration in modeling such systems. Simple potentials are parameterized under bulk homogeneous conditions and may give poor descriptions of the inhomogeneous environment near a crack tip. In an effort to employ a classical potential that is responsive to a rapidly changing environment, Omeltchenko and coworkers ° simulated a graphite sheet modeled by more than a million particles. The authors used a reactive bond order potential developed by Brenner. In this approach, the total potential energy can be written as follows ... 

Rees et al. [342] provide an elaborate description of two-microemulsion synthesis of CaS04 which clearly indicates a dependence of the particle morphology on the w value and concentrations of the other constituents. As an example, in the system Ci2E4/cyclohexane/aqueous Ca-nitrate or Na-sulfate, a progressive change in the value of w from 2 to 20 changed the particle morphology from nanospheres to nanorods via nanowires. 

Menna P, Di Francia G, La Ferrara V (1995) Porous silicon in solar cells a review and a description of its application as an AR coating. Sol Energy Mater Sol Cells 37 13-24 Najar A, Charrier J, Pilasteh P, Sougrata R (2012) Ultra-low reflection porous silicon nanowires for solar cell applications. Acta Phys Pol A 122 1121-1124 Nelson J (2003) Physics of solar cells. World Scientific, Washington, DC Panek P (2004) Elfect of macroporous silicon layer on opto-electrical parameters of multicrystalline silicon solar cells. Opto Electron Rev 12 45—48... 

In an interesting study, Sankaranarayanan et compared bimetallic nanowires with clusters and the macroscopic crystals. They performed molecular-dynamics simulations using the Sutton-Chen potential for an approximate description of the interatomic interactions. They considered two systems, Pd-Rh and Pd-Cu. As initial structures, they considered cut-outs of the infinite, crystalline fee or hep structures. Subsequently, the two types of atoms were distributed at those atomic positions that led to the... 

This chapter provides an overview of nanotechnology-themed experiments for general chemistry laboratory instructors. Prepartions of CdS, Fc304, Ag and An nanoparticles and Ni nanowires are presented as examples. Each experiment s description includes theoretical backgroimd, procedmes and applications of the nanomaterial. Additional resources for teaching nanotechnology to freshmen and designing new experiments are provided. 

In the chemical vapor deposition (CVD) process, a molecular precursor is used [11-13]. Here, as the catalyst absorbs an increasing amount of material it eventually becomes supersaturated, at which point material is deposited at the catalyst-substrate interface (Figure 3.1b), thereby establishing nanowire formation (Figure 3.1c). Extended formation of the nanowire can be maintained as long as a sufficient quantity of reactant is present, and the temperature of the catalyst is maintained above the melting point. If either of these conditions is not met, nanowire formation will cease. Based on the above description of the VLS mechanism, it is clear that the catalyst dictates whether or not nanowire formation will occur. 

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