Doping Samples

A solvent free, fast and environmentally friendly near infrared-based methodology was developed for the determination and quality control of 11 pesticides in commercially available formulations. This methodology was based on the direct measurement of the diffuse reflectance spectra of solid samples inside glass vials and a multivariate calibration model to determine the active principle concentration in agrochemicals. The proposed PLS model was made using 11 known commercial and 22 doped samples (11 under and 11 over dosed) for calibration and 22 different formulations as the validation set. For Buprofezin, Chlorsulfuron, Cyromazine, Daminozide, Diuron and Iprodione determination, the information in the spectral range between 1618 and 2630 nm of the reflectance spectra was employed. On the other hand, for Bensulfuron, Fenoxycarb, Metalaxyl, Procymidone and Tricyclazole determination, the first order derivative spectra in the range between 1618 and 2630 nm was used. In both cases, a linear remove correction was applied. Mean accuracy errors between 0.5 and 3.1% were obtained for the validation set. 

Fig. 7. Susceptibility of the pristine sample (+) and of the K-doped sample (closed circle). The open circle points correspond to the susceptibility of the K-imercalated powder before the film deposition procedure [35].

Figure 7-33. ODMR spectra of pristine and C o-doped DOO-PPV. Inset hall-field signal of doped sample.

Fe4Sni2S32) to 2.319 A in the Si-doped compound studied here. This may be due to the doping of Si atoms. The size of Si" is smaller in comparison to the size of Cu and this would lead to the smaller Cu-S bond length in the Si-doped compound [22]. The Fe/Sn-S distances do not show much change, being 2.536 A in the pure compound and 2.5365 A in the Si-doped sample. Selected bond distances are given in Table 15.2. 

In the first three cycles, the capacity of the alanate is high for both materials, the titanium metal-doped and the nitride-doped material. However, after 15 cycles the hydrogen capacity decreases significantly below 4% for the titanium metal-doped sample, whereas for the nitride-doped sample the capacity remains high at about 5% hydrogen. 

The loss of phase complexity in both systems may be attributed to an increase of the PS/PEO and PI/PEO interaction parameters. Because LiClC is selectively located in the PEO domains, the interaction parameters (/ps-peo and xpi-peo ) must increase, leading to variations in domain type and dimension. As the lithium salt increases the polarity (and presumably the solubility parameters) of the PEO domains, the interfacial tensions between PEO and PI, and PEO and PS are elevated. Thus, a reduction in the overall PEO interfacial area is required, which necessitates additional chain stretching. In consequence, the CSC structure becomes dominant when comparing doped and non-doped samples [171] (Figs. 54 and 55b). 

Except when alloys or highly doped samples are being considered, it leads to a lack of multiplicity in the NMR peaks, even for inherently oriented single crystals, because of the presence of one unique atom of each element in the unit cell. 

The addition of Na also impacted the Pt-CO linear u(CO) to bridged u(CO) band ratio, referred to as L/B.52-53 The presence of the Na dopant favored an increase in the amount of bridge-bonded CO, where the ratio of 8.3 for no alkali doping decreased to 1.5 for the 2.5% Na-doped sample. Competing viewpoints (e.g., electronic, geometric) regarding the nature of the change in the L/B ratio are summarized in previous works.1-49... 

Figure 2 shows that samples with boron concentrations ranging over four orders of magnitude can be effectively treated. The samples were hydrogenated at 122°C the upper three samples for one hour, and the most heavily doped sample was hydrogenated for four hours. Note that the spreading resistance increases toward the surface. The value of resistivity... 

Fig. 2. Spreading resistance profile of four B-doped samples of (100) Si hydrogenated at 122°C. The three higher resistivity samples were hydrogenated for one hour the lowest resistivity sample was treated for four hours. The resistivities were obtained from a calibration curve. Note the greater penetration depth of atomic hydrogen as the boron concentration decreases.

Heating the B-doped samples above 200°C in vacuum to dissociate the hydrogenated complex results in flat spreading resistance (Rs) at the original bulk value. A second exposure to Hj restores the increased Rs at the surface. These are crucial experiments that demonstrate that hydrogen is involved and that the process is reversible and reproducible. 

Also, thalium in Si was neutralized in a separate experiment. The more complex behavior of the Al-doped sample, showing a tenfold abrupt jump in Rs, is not yet understood, although this behavior is reproducible after treatments at other temperatures and durations. 

An important point regarding the hydrogen diffusion data described above is that the diffusion coefficient is not uniquely defined but rather depends on the time for which the sample is annealed. This is clearly shown in Fig. 14 where DH is plotted against anneal time in hours for a 10 2[B2H6]/[SiH4] doped sample, annealed at 200°C (Street etal., 1987b). The diffusion coefficient decreases by nearly a factor of five as the annealing time is increased from 10 min to nearly 200 hours. DH can be approximately described by a power law,... 

The lower activation energies found for p-type a-Si H using the evolution technique may be due to microstructure in the films grown with a He carrier gas. The higher D0 obtained in doped samples using the concentration profiling technique results from the correction of the data to a constant diffusion distance L = 1000 A (Jackson et al., 1989a). 

Yo.iLao iCe0 8Oi 9 Lao.2Ce0,8Oi 9 Yo Ceo.sOi 9 <7 was about the average conductivities of the single-doped samples [139]... 

The threshold fluence decreases with increasing dopant concentration and for the lowest concentration where ablation is observed (0.2% polyimide) the threshold fluence is about 0.7 J/cm2 at 248 nm and about 0.9 J/cm2 at 308 nm. Additionally, at fluences around 10 J/cm2, the maximum measured etching rates at 248 and 308 nm are about 3 and 6 pm/pulsc, respectively. While the etching rate for the 248 nm ablation of the 0.2% polyimide-doped sample has begun to saturate, the corresponding curve for the 308-nm ablation is still increasing. In comparison, the threshold fluence for the ablation of neat PTFE using 300 fs... 

Fig. 1.8 I mmersion double cell separated by necessary. Illumination is needed for moder-the fixture of the silicon electrode. Note that ately doped samples, to generate a current in...

For not too low doped samples (D W), however, the contribution of 1SCR is usually negligible. If the surface recombination velocity at the illuminated front is low, IBPC then only depends on sample thickness D, illumination intensity eP, and minority charge carrier diffusion length ID. 

Thus, the sign of the surface charge contributed by the chemisorbed particles may be determined if one obtains from experiment the sign of Aic (in the case of a doped sample, if the type of conductivity is known) or the sign of Ay> (if the polarization effect can be neglected) i.e., these... 

---