Quantum tunnel effect nanoparticles

Nanoparticles have been widely used in optical, resonant, electrical, and magnetic fields. The small size effect, large surface effect, and quantum tunnel effect demonstrate the unique properties of nanoparticles. It is necessary to study the techniques of nanoparticle preparation to meet the developments in nanotechnology and nanomaterials. In this section, we describe work carried out in our laboratory on the syntheses of several nanoparticles and nanocomposites and the study of their properties. 

Nanoparticle materials are important because they exhibit unique properties due to size effects, quantum tunneling, and quantum confinement. As sizes of embedded particles are reduced to the nanometer scale, the surface-to-bulk ratio increases significantly. Therefore, surface effects can dominate bulk properties and an understanding of nanosurfaces becomes important. In this chapter, we discuss characterization of vacancy clusters that reside on surfaces of embedded nanoparticles as well as studies on the correlation of surface vacancy clusters to the properties of the nanomaterials. 

Another characteristic feature of electron behavior in nanoparticles is the dmrge confinement, Le. the presence of the potential which holds the carriers in the particle and thus determines the maximal size carrier motion ( partide in a box model). It is the presence of a confinement but not the discretization caused by finite quantity of atoms in a partide effect (as described above), which is responsible for most of the so-called quantum size effects. The effects referred to originate in the very fact, that the particle size is comparable to electron or hole De Broglie length and to form the spatially stable solutiem both finite size and boundary conditions are to be taken into account In the majority of models the finite character of confinement border potential (and hence the possibility for the carrier to escape the partide or tunnel to another partide) has not been taken into account. In Sect. 5 of our review we will show that the variety of effects determining the cooperative behavior of highly-filled composites are caused by this possibility. 

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