Electron mean free path table

For metallic superconductors the electron-phonon interaction accounts for the superconductivity of low-7] oxide conductors. For all of these materials the electrical parameters indicated in Table 4.2-11 depend on the electron mean free path, and thus on the resistivity p, of the material in the normal state. The quantitative relation for Hc2 is given by... 

Since an additional ellipsometric measurement would be needed to determine the carbon-overcoat thickness, the ellipsometric measurement of PFOM thickness directly on non-carbon-overcoated silicon is more straightforward. Silicon strips and wafers were dip coated with PFOM. The PFOM thickness measnred by ellipsometry and the dIX from XPS are listed in table 4.8. The thickness measured by ellipsometry was divided by the dIX from XPS for each sample (last two columns in table 4.8). The experimentally determined average electron mean free path for PFOM film is X = 2.66 nm. Sliders were dip coated with PFOM at the same conditions as the silicon wafers and strips, and dIX was measured on the air bearing surface of each slider by XPS. These dIX were multiplied by A, = 2.66 nm, as determined above, to estimate the PFOM thickness on the air bearing surface. These results are listed in table 4.9. The concentration of the PFOM solution was 650 ppm, and the withdrawal rate was 1.6 mm/s. 

The electron mean free path of A, = 2.66 nm is within the range of mean free paths reported for polymer thin films on surfaces [8]. Equation (4.4) was used to estimate the PFOM thickness on air bearing surfaces from dIX. The values of dIX and PFOM film thicknesses are given in table 4.9. The PFOM film was 0.5-0.7 nm thicker on the carbon-overcoated air bearing surfaces (table 4.9, column 3) and on the carbon-overcoated rows (table 4.7, columns 3 and 7) than on the silicon wafers (table 4.8, column 3). This is attributed to the difference between the surface chemistry of the SiOj surface of the uncoated silicon and that of the carbon overcoat. 

Integration of these component peaks, with appropriate corrections applied for different photoionization cross-sections and inelastic mean free paths, gives the electron populations listed in Table 4. The atomic charges obtained are consistent... 

Here we will summarize, from the previous subsections as well as from literature, some typical properties and representative parameters (see table 6) of the superconducting state of YNi2B2C and LuNi2B2C where completeness is not attempted. These materials are usually clean-limit type II superconductors. However by substitutional disorder on the rare earth site in (Y,Lu)Ni2B2C or on the transition-metal site in Lu(Ni,Co)2B2C the residual resistance ratio RRR = p(300 K)/p(Tc), where p(T) is the normal state resistivity, and the mean free path / of the electrons in the normal state can be considerably reduced... 

Table 3-1. Similarity Parameters Deseribing Eleetron-Neutral Collision Frequeney, Eleetron Mean Free Path, and Electron Mobility and Conductivity at j = 1 30 V cm/Torr...

The electrical conductivity is mainly determined by the carrier density (n), relaxation time (r), and effective mass (m) of the carrier (electrical conductivity, cr = ne T/m). According to the loffe-Regel criterion, the interatomic distance is considered as the lower limit to the mean free path (A) in a metallic system. Hence, for a metallic system, kfX > 1, where kfX = [/j(37r ) / ]/(c pn / ), kfis the Fermi wave vector, and p is the electrical resistivity [1125, 1126]. In highly doped conducting polymers, n 10 per unit volume, m is nearly the electron mass, A is a few tens of angstroms, and kfk 1-10 at room temperature. The mean free path is limited by both the interchain transport and the extent of disorder present in the system. The details about metallic conducting polymers are shown in Table VI [1127]. 

TABLE 1. Electron Inelastic Mean Free Paths of Elemental Solids in A (10 m)... 

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