Trilayer

Fig. 24. Adsorption of lithium on the internal surfaces of micropores formed by single, bi, and trilayers of graphene sheets in hard carbon.

Figure 30 shows a series of ealeulated patterns for carbon samples with a fraction, f, of carbon atoms in randomly oriented single layers, a fraction 2/3(1-f) in bilayers and a fraction l/3(l-f) in trilayers [12]. These cuiwes can be used to estimate the dependence of the ratio, R, defined by Fig. 29, on the single layer fraction. Figure 31 shows the dependence of R on single layer fraction for the calculated patterns in Fig. 30, and for another set of calculated patterns (not shown) where the fraction of carbon atoms in bilayers and trilayers was taken to be /2(l-f) [12]. Both curves in Fig. 31 clearly show that R decreases as the single layer content of the sample increases and is fairly insensitive to how the carbon is distributed in bilayers and trilayers. 

Fig. 30. Calculated (002) Bragg peaks for various single layer fraetions of the sample from referenee 12. The ealeulations assumed that a fraetion, f, of the earbon was in single layers and that fractions 2/3(l-f) and l/3(l-f) were included in bilayers and trilayers respectively.

Fig. 31. The dependence of R on single-layer fraction for the calculated patterns of Fig. 30, and for a second set of calculations where the fraetion of earbon atoms m bilayers and trilayers is equal [12].

As examples for our investigation we have chosen Fe/Cu/Fe bcc (001) and Co/Cu/Co fee (001) trilayers. A trilayer consists of two semi infinite crystals of Fe separated by a paramagnetic Cu spacer. The entire trilayer has the same crystal structure which means that all effects from lattice relaxations are excluded. The experimental lattice constant of bcc Fe was chosen for the Fe/Cu/Fe bcc trilayers, whereas for the Co/Cu/Co fee trilayers we used the lattice constant of fee Cu. 

In Fig. 4 we show how the interlayer coupling strength is decreasing continuously as a function of the intermixing concentration. The behaviour is very similar to the case of interface intermixing in Fe/Cu/" trilayers shown in Fig. 2. 

Figure 1. The magnetic interlayer coupling in Fe/Cu/Fe bcc (001) trilayers. The squares denote the coupling energies for the pure trilayer and the circles the coupling energies for the dilute trilayers with 50% of intermixing in a single monolayer at each Fe/Cu interface. One example of an averaged interlayer coupling is indicated by the diamonds.

Figure 12-9. j(E) plols of diodes containing a 100 mil thick DASMB layer (open circles), a DASMB/ PBD PS layer of lolal thickness 80 nm (open triangles) and a trilayer assembly of a 15 nm thick PTV layer, a 20 nm thick DASMB layer and a 40 nm thick PBDtPS layer (open squares). 

Trilayer structures offer the additional possibility of selecting the emissive material, independent of its transport properties. In the case of small molecules, the emitter is typically added as a dopant in either the HTL or the ETL, near the interface between them, and preferably on the side where recombination occurs (see Fig. 13-1 c). The dopant is selected to have an cxciton energy less than that of its host, and a high luminescent yield. Its concentration is optimized to ensure exciton capture, while minimizing concentration quenching. As before, the details of recombination and emission depend on the energetics of all the materials. The dopant may act as an electron or hole trap, or both, in its host. Titus, for example, an electron trap in the ETL will capture and hold an election until a hole is injected nearby from the HTL. In this case, the dopant is the recombination mmo.-... 

Figure 3. Cross-sectional views of PP/PE/PP trilayer separator before and after exposure to short-circuit conditions.

PP/PE/PP trilayer separators 556 practical batteries 19-61 precipitation, solid electrolytes 540 precursors... 

To determine whether the 8CB droplets condensed above 41°C (trapped in the isotropic phase) sit on a trilayer or on bare silicon, we used the ATM tip to mechanically spread the droplets and thus accelerate their conversion to a stable configuration. The SPFM images shown in Fignre 15 were obtained after such tip-induced spreading. A layered structure with 32-A-high steps typical of the smectic phase is obtained. The first, or bottom, layer is 41 A thick, while the layers above it are all 32 A thick. This indicates that the bottom layer of the film is a trilayer and that the remaining snbstrate is dry silicon, i.e.. 

Figure 7. TEM images of (a) bilayer of 3.1 nm Fe34Pt

O—Ti02—O trilayers and reducing computational approximation errors, Thompson and Lewis [71] have been able to achieve excellent quantitative agreement with the experimental data. In the same paper, it has also been pointed out that a minimum of five trilayers slab is required to recover the experimental H—O bond lengths [71]. 

The latter issue was addressed more recently by Hamilton et al. who developed a trilayer composite consisting of CPP, articular cartilage (CEP), and NP tissue [125]. By sequential seeding of chondrocytes onto the CPP surface followed 2 weeks later by seeding NP cells onto the matrix produced by the chondrocytes, the authors were able to form a tissue composite construct. Although it appeared that the NP cells were able to maintain a rounded morphology, the interfacial shear load required to... 

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