Point contact spectroscopy

Keywords Chemical sensors Point contact Exhaled air analysis Point-contact spectroscopy Organic conductors Noninvasive diagnostics Chronic dyspepsia... 

Naidyuk YuG, Yanson IK (2004) Point-contact spectroscopy. Springer Verlag, New York... 

POINT-CONTACT SPECTROSCOPY OF TWO-BAND SUPERCONDUCTOR MgB2... 

Keywords point-contact spectroscopy, MgB2, two-band/gap superconductivity, electron-phonon interaction... 

Point-contact spectroscopy of two-band superconductor MgP2... 

MODERN APPROACHES IN POINT-CONTACT SPECTROSCOPY AND THEIR APPLICATION TO PROBE NANOCLUSTERS IN MESOSCOPIC MATERIALS... 

Abstract Modem approaches in point-contact spectroscopy were used for the... 

Key words Point contact spectroscopy, layered compounds, nanoclusters, superconductivity. 

FIGURE 37 Temperature dependence of the superconducting gap A of DyNi2B2C obtained by point-contact spectroscopy (from Yanson et al., 2000a). 

The zero-approximation in expansion of I(V) in d/l is the ohmic current considered by Sharvin [5]. From the Sharvin s formula the characteristic size d of the contact can be determined in the ballistic limit. The second derivative of the first approximation in expansion of I(V) in d/l is directly proportional to the spectral function of electron-phonon interaction (PC EPI) gpc w) = apc (w) F (w) °f the specific point-contact transport both in the normal and in the superconducting states [1, 6, 7], This term is the basis of the canonical inelastic point-contact spectroscopy (PCS). Here, ot2pC (oj) is the average electron-phonon matrix element taking into account the kinematic restriction imposed by contact geometry and F (oj) is the phonon density of states. 

Low temperature (LT) point-contact spectroscopy preceded LT-STM as a means of measuring the energy gap on materials where an ideal oxide barrier could not be fabricated. Typically, noble metal tips were used. Figure 6.4 shows an experimental set-up for one of the earlier designs [6.12] The 7(F) and d//dr measurements taken with this apparatus for one of the first poly crystal-... 

The pressiue dependence of the electrical resistivity of YbCuAl was investigated (Alami-Yadri et al. 1998, 1999a,b) up to 8 GPa. The resistivity at 300 K decreases with increasing pressure. At 8 GPa a dependence occurs at low temperature (Fermi-liquid behavior), and the Kondo temperature decreases with increasing pressure. The experimental setup for these measurements was presented by Jaccard et al. (1998). Furthermore, point-contact spectroscopy was used to measure the interconfigurational excitation energies and conduction-electron lifetime width of valence-fluctuating YbCuAl (Bussian et al. 1982). 

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