Semiconducting samples

Attempts to convert organic metals into superconductors have also been undertaken. The first organic superconductor was (TMeTSeF) PF6. The transformation took place at 0.9 K and 1 hPa. Substitution of Cl()4 for PF6 led to a superconductor even at normal pressure and temperature of 1.2 K. In addition, the salt of the ET cation radical with iodide was prepared. It also showed superconductivity at normal pressure. Superconductivity temperatures increased up to 7 K with iodine contents. It was established that a semiconducting sample of (ET)J LT (the so-called a-phase) transformed into the superconducting (3-phase upon heating (Baram and others 1986). 

The thermistor effect provides an indirect way to realize nonlinear current-voltage characteristics and (differential) negative resistances in conventional semiconducting samples which takes advantage here of sample self-... 

The active components of the STM are the two electrodes, a sharp metallic probe, and a conductive (or semiconductive) sample, one of which is moved relative to the other in a x-y grid utilizing piezoelectric tubes, disks, or rods for precise positioning with angstrom accuracy. The STM tip (electrode 1) is typically tungsten (UHV conditions) or Pt/lr (ambient conditions), although other noble metal tips have been used. The second electrode is the conductive or semiconductive sample to be analyzed or manipulated. 

Aside from contact electrization, local accumulation of charges takes place as a result of mechanical separation and formation of a double electrical layer (DEL). Mechanical separation of charges is brought about by exfoliation of adhesive films from the metal or semiconducting samples. DEL may arise in response to chemical interactions of two phases or as a result of selective adsorption of similar ions, e.g. in the presence of oriented dipoles on the contact surface of one of the phases. Electrization can also be induced by the donor-acceptor (DA) interaction, since in agreement with the electrostatic theory of adhesion DEL are formed at the interface of two substances at the expense of DA links and govern the efficiency of adhesive interactions [41]. 

Reaction of NO2 with models of metaUic (6,6) and semiconducting (10,0) carbon nanotubes led to ketene formation as indicated by the Cls photoemission signals, with calculated Cls core-levels for the ketene carbonyl of 286.67 and 286.33 eV for the (6,6) and (10,0) nanotubes, respectively, in semi-quantitative agreement with the experimentally observed features in the C Is spectra at 286.4 and 286.2 eV for the metaUic and semiconducting samples, respectively. Computations of the stmcture of a conceivable product containing ketene and epoxide groups were reported (Figure 4.10). 

In order to measure the carrier concentration directly, a method is applied which uses the Hall effect. The simplest setup is shown in Figure 1.15. Here a voltage is applied to a semiconducting sample in the r-direction and a magnetic field is applied along the z-direction. The resulting Lorentz effect causes a force... 

The contact area between the liquid meniscus and the surface constitutes a working electrode on (semi)conducting surfaces, and so any redox-active species (molecules or ions) present in the solution can be oxidized or reduced at the substrate, causing a current flow that is measured. Additionally, as we describe later, the SECCM nanopipette can be used to deliver nanoparticles to a surface. " Typically, the potential of the (semiconducting sample is held at ground, and the... 

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