Semiconducting magnet

Microspheres based on metal-containing polymers should exhibit interesting redox, semiconductive, magnetic, and photonic properties intrinsic to the polymeric materials, and may prove useful for a variety of applications. The most common methods for microsphere preparation involve the use of steric stabilizers, which may adversely affect the properties of the resultant materials. This problem can be avoided by the use of a precipitation polymerization methodology, which allows for the autostabilization of the polymer microspheres without addition of stabilizers. This... 

The extensive NMR work on the rare-earth pnictides (RN, RP, etc.) was reviewed in section 2.2.3 and 2.2.3.2. Various of the rare-earth chal-cogenides (oxides, sulfides, etc.) also form in the cubic rock-salt structure, in particular those of Eu and Sm. The europium monochalcogenides are semiconducting magnetic materials whose properties have been reviewed by Wachter (1972) also see ch. 19. Both NGR and NMR methods afford opportunity to study these compounds, and the work on oxides has been reviewed in the fore-going section (section 2.3.3). Table 18.24 provides a brief summary listing of experimental work. 

Although it is required to refine the above condition I in actuality, this rather simple but impressive prediction seems to have much stimulated the experiments on the electrical-conductivity measurement and the related solid-state properties in spite of technological difficulties in purification of the CNT sample and in direct measurement of its electrical conductivity (see Chap. 10). For instance, for MWCNT, a direct conductivity measurement has proved the existence of metallic sample [7]. The electron spin resonance (ESR) (see Chap. 8) [8] and the C nuclear magnetic resonance (NMR) [9] measurements have also proved that MWCNT can show metallic property based on the Pauli susceptibility and Korringa-like relation, respectively. On the other hand, existence of semiconductive MWCNT sample has also been shown by the ESR measurement [ 10], For SWCNT, a combination of direct electrical conductivity and the ESR measurements has confirmed the metallic property of the sample employed therein [11]. More recently, bandgap values of several SWCNT... 

The k p method provides analytic descriptions on electronic states of CNT. It shows, for example, that the band gap of a semiconducting CNT is inversely proportional to the diameter because of a linear dispersion of the bands. It is suitable also for descriptions of the electronic motion in external perturbations such as electric and magnetic fields. 

Fig. 3. Energy gap versus magnetic flux passing through the tube cross section for metallic (v=0) and semiconducting (v= l) CNT.

The electron wave function becomes localised in the top and bottom part of the cylindrical surface where the effective magnetic field perpendicular to the tube surface is the largest. Thus the boundary condition along the circumference direction becomes less important in high magnetic fields as has been discussed in Sec. 2. Consequently the distinction between metallic and semiconducting... 

The surface of a material exposed to the environment experiences wear, corrosion, radiation, electrical, or magnetic fields and other phenomena. It must have the properties needed to withstand the environment or to provide certain desirable properties, such as reflectivity, semiconductivity, high thermal conductivity, or erosion resistance. Depositing a coating on a substrate produces a composite material and, as such, allows it to have surface property, which can be entirely different from those of the bulk material. 

Wei S-H, Zunger A (1986) Alloy-stabilized semiconducting and magnetic zinc-blende phase of MnTe. Phys Rev Lett 56 2391-2394... 

The bis(phthalocyaninato) lanthanide (III) complexes have generated a great deal of interest because they are found to show electrochromic and semiconducting properties [87, 203]. They have been characterized by a range of spectroscopic methods, but much research interest has been directed towards understanding the f-electronic structures and their magnetic properties. In order to understand... 

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