Semimetal particles

RKKY interactions were first considered on an atomic scale, where the oscillation period is on an A scale. In nanostructures, the fast oscillations do not average to zero but increase with the size of the embedded clusters or nanoparticles. However, the increase is less pronounced than that of magnetostatic interactions, and for particles sizes larger than about 1 nm, the magnetostatic interactions become dominant [27, 29], In semiconductors and semimetals, such as Sb, the low density of carriers means that kF is small, and the period of the oscillations is nanoscale [16, 28], This contributes to the complexity of the physics of diluted magnetic semiconductors [30, 31]. 

For a semimetal (such as carbon), this feature is clearly visible in a qualitative plot of the (11) fork= 1 and k = N in the two cases (fundamental and excited), as shown in Fig. 3. As can be seen, the metallic behavior appears only in a cluster with a significant number of atoms in the presence of fewer atoms, the particle s behavior is similar to that of a semiconductor, i.e., it shows a forbidden band dependent on the number of atoms in the particle. The discreteness of the electronic level structure was discussed in detail by Kubo and Kawabata [59,60], and reviewed by Halperin [58]. 

As a solution-based materials synthesis technique, the microemulsion-mediated method [10-18] offers the unique ability to effect particle synthesis and particle stabilization in one step. The solubilized water droplets serve as nanosize test tubes, thus limiting particle growth, while the associated surfactant films adsorb on the growing particles, thereby minimizing particle aggregation. The purpose of this chapter is to review the literature on the microemulsion-mediated synthesis of metal hydroxides and oxides the definition of a metal is extended here to include the semimetal silicon. Since metal oxides are frequently produced by decomposing metal salts, aspects of the literature on microemulsion-derived metal salts are also considered. In principle, any previously established aqueous precipitation chemistry can be adapted to the microemulsion synthesis technique. Accordingly,... 

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