Temperature and doping dependence

The response for low doping closely follows a two-fluid type behaviour for low hole doping but which deviates from this at higher doping levels. 

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The temperature and doping dependence of the energy gap can also be derived as follows. The energy to remove one electron pair from the condensate at absolute zero is... 

Temperature and doping dependence of density of condensed electrons... 

Let us look at the temperature- and doping-dependence of the Raman spectra of two representative samples (Ml and M5) in Fig. 2. At room temperature we observed three pronounced phonon modes at 270,... 

Figure 3. Theoretical phase diagram and doping dependence of the transition temperature predicted by our theory for the parameters D = 5, V = 0.564eV compared with the well known experimental doping Te curve shown above. The superconducting (SC), insulating (I) and metallic phases are characterised by use the Mott-Edwards-Sienko relation [23,24,28] as described in [15].

Finally, any doping leading to a finite conductivity cr will lead to a loss contribution according to tan5 = conduction mechanism like hopping conductivity may give rise to complicated temperature and frequency dependences, which cannot be discussed in detail here. 

The field, temperature, and concentration dependencies of electron mobilities are similar to hole mobilities. These have been discussed in the preceding chapter and need not be further discussed here. Tables 2 and 3 summarize literature references of activation energies of vapor-deposited glasses and doped polymers. Tables 4 and 5 summarize similar data concerning the widths of the DOS. 

In this report, we present resistivity measurements of K jC o as a fimetion of tempser-aturc and doping. We used ultrahi -vacuum (UHV) molecular beam deposition to dope polycrystalline 60 films with controlled quantities of K while continuously monitoring the time-dependent film resistance near room temperature. The method gives the time, temperature, and concentration dependence of the resistance as well as an estimate for the difiusivity of the K dopant. The stoichiometry of the superconducting phase, which corresponds to a minimum in the... 

Numerous Br SSNMR studies have been carried out on AgBr, many of which focused on the addition of dopants and their effects on the bromine SSNMR spectra (see below).The temperature and time dependence of the Br NMR signal of plastically deformed AgBr (both pure and NaBr doped) have also been discussed and related to the density of lattice dislocations. The reader is referred to Table 9 for additional information on AgBr. 

Dielectric and conductivity measurements of NHs-doped ice were discussed by Arias, Levi, and Lubart (I). They observed a dielectric dispersion which, for all concentrations (2 X 10"5M to lO M), and temperatures (— lO C. to —40°C.) was qualitatively similar to that for pure ice or ice of slight impurity content (Figure 18). The a.c. conductivity curves also look like those of Figure 18. Above lO M the conductivity was independent of concentration and about equal to the d.c. conductivity. No specific expressions were given for the temperature and concentration dependence. These results point to a role for NH3 in ice quite different from HF. Ionization appears to be much smaller in ice doped with the former or the difference is caused by the smaller mobility of hydroxide ions as compared to hydrogen ions. 

The measurements of ion transport numbers made by method of EMF and by sign of thermo-electric force reveal, that in all studied materials at Po2 > 10 Pa and in air the electronic conductivity of p-type (hole conductiviy) predominates, and at P02 < 10-1 Pa the electrical conductivity is predominantly ionic. The transport number of ions f alters depending on oxygen partial pressure, temperature and doping from 0,9 down to 0,1. 

Feigerman et al. 1994, Kopnin 1996), there is considerable uncertainty about why, in certain cuprates, is negative while is positive. Several groups have used eq. (6) to analyze the Hall conductivity data of different high-temperature superconductors in order to ascertain whether eq. (6) provides a satisfactory description of the Oxy(B) data, and, if it does, to determine how the two coefficients C i and C2 depend on temperature and doping. 

The thickness of PS layer is also one of the factors that influence the contact behavior. As thin PS layer show rectifying characteristics while thick PS layer show an almost symmetric one, Ben-Chorin (Ben-Chorin et al. 1994) proposed that the rectifying barrier is at the interface between PS and the doped substrate. It was also suggested by them (Ben-Chorin et al. 1994) that the usual diode structure formed by a metal contact, a PS layer, and a doped substrate can be visualized as a series combination of a voltage-dependent resistance and a rectifying barrier. Their study shows that the temperature- and voltage-dependent conductivity relationship follows Poole-Frenkel (PF)-t3 e conduction, where transport mechanism in high fields involves field-enhanced thermal excitation from Coulombic traps ... 

Buchler MG, Ryan MA (1997) Temperature and humidity dependence of a polymer-based gas sensor. Proc SPIE 3082 40-48. http //enose.jpl.nasa.gov/publications/sensors/97-0482.pdf Cabala R, Meister V, Potje-Kamloth K (1997) Effect of composite doping on sensing properties of polypyrrole. J Chem Soc Faraday Trans 93 131-137... 

Zinsou PK, Vergnoux D, Ablart G, Pescia J, Misra SK, Berger R. 1996. Temperature and concentration dependences of the spin-latice relaxation rate in four borate glasses doped with Fe203. Appl Magn Reson 11 487-492. 

V. Swaminathan and S. M. Copley, 1975, Temperature and orientation dependence of plastic deformation in GaAs single crystals doped with Si, Cr, or Zn J. Am. Ceram. Soc. 58, 482-485. 

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