Doping dependence

All this pertains to the dissociation reaction (132) or its inverse (126). Since other dissociation reactions, inverse to (128)—(130), may becomes dominant in strongly p-type regions, the dissociation lifetime r2 may well be shorter here than in the weakly n-type region of the small step in Fig. 24. And if an H species exists, there could be a similar doping dependence of the lifetime of H2 in strongly n-type material here, however, relevant data are almost entirely lacking. 

For doping-dependent anodic etch stops in HF, a general hierarchy of dissolution is observed [La5] illuminated n-doped and n+-doped areas are most easily dissolved, followed by p+-doped areas. Next likely to be dissolved are p-type areas. Moderately n-type doped areas kept in the dark are least likely to be etched. This hierarchy corresponds to the potential shift of the I-V curve in the regime of PS formation [Gal, Zh5]. 

The doping dependence of the PS formation process and the possibility of transforming PS to oxide at relatively low temperatures has been used to form dielectrically isolated silicon islands, as shown in Fig. 10.23. 

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... 

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].

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

In summary the account of interband vibronic interactions in the doping-dependent electron spectmm of cuprates allows to explain the presence of two normal state pseudogaps at underdoping and the extent of the pseudogap behaviour to the whole doping region. Such results are far away from the basic Jahn-Teller effect framework and illustrate the brightness of the basic vibronic hybridization idea. 

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,... 

X. L. Liu, and C. W. Zhou, Surface treatment and doping dependence of ln2C>3 nanowires as ammonia sensors , Journal of Physical Chemistry B 107, 12451 (2003). 

Figure 2. (a)The subtracted TEP (AS = S(T) - SpT)) data with linear fitting function Sl(T) = aT+f) for typical LSCO samples. The inset shows the doping dependence of the slope (a) and the offset (J3) for SL(T). (b) Characteristic temperatures, Tc, Th, Tj and Tp (See the text.) with the pseudogap temperatures reported from various experiments for LSCO (Ref. [1]). 

Figure 3. (a)The temperature dependence of TEP is reproduced with our mixed state model, (b) Hole doping dependence of one of fitting parameters T with the characteristic temperatures, Th, Tt and Tc (See the text.). Fitting parameters, y and p are also shown with variation of doping concentration in the inset. 

The independence of the SCF and the pseudogap seems to be confirmed when three characteristic temperatures, Tc, Tc and T, are compared. This is done in Fig. 3, where the doping dependence of Tc, Tc and 7 is represented. The data for T where taken from Ref. [9], This figure illustrates that in the underdoped La. Sr.CuCL superconductors not only Tc but also T° is much lower than T and that the doping behaviour of both Tc and T° is very different from the one of T. ... 

Pseudogap behavior is most easily identified at temperatures below T but well above the superconducting transition temperature. A simple expression for the doping dependence of T for the 2-1-4 materials that is consistent with the Nakano analysis and the Matsuda experiments is... 

It is also important to note that the slave boson method itself possess two different types of symmetry with respect to doping. From the doping dependence of the effective copper-oxygen overlap t for Ap(i/t0 large enough, symmetry with respect to zero doping emerges [8], since... 

The observed evolution of the shape of the band-structure upon doping satisfies the Luttinger sum rule [9], It should be noted that only in the Anderson lattice-like limit of the Emery model it is possible to obtain the observed evolution of the FS upon doping. In all other cases, the oxygen symmetry of the FS can be attributed to the (non-renormalized) oxygen band and therefore the strong doping dependence of the band structure cannot be expected. 

Measurements of the doping-dependence of the slopes of the electron bands around the nodal points [12] show almost no change with doping of the slope... 

The TEP results depend strongly on np, and reproduce very well the doping-dependent experimental behavior [27, 28], The position of the maximum in S depends on the choice of cop, and it may occur below or above Tc (the existence of a PG may shift it to a higher temperature than predicted here). 

Early diffraction patterns showed a small number of reflections only [60]. The degree of order that remains in a sample after doping depends... 

More evidence that thermal equilibrium is not attained is the existence of a memory effect. It has been observed that the kinetics of doping depends on the wait time spent in the insulating state [15]. After 105 s in the undoped state, steady-state behavior is still not obtained. This means that a slow relaxation process is taking place in the film maintained in the insulating state. This effect has been quite well characterized, but no microscopic explanation has yet been given [16]. 

Figures 8 and 9 show the temperature dependence in pure samples and the doping dependence with regard to positive and negative doping. While the response to Cd2+ doping (Cd Ag) follows exactly the theory (Figs. 8 and 9), S2 -doping (S Ci) suffers from interaction effects (see below), but the absence of a minimum is in qualitative agreement with the fact that an increase of [A ] is effected (Fig. 9, l.h.s.). Figures 7 and 8 display the succession ofintrinsic (C ) and the extrinsic...

Fig. 5.9, The gas phase doping dependence of the defect density and occupied band tail density, obtained in different experiments (Street et al. 1985).

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