Superlattice formation

Bartlett P, Ottewill R FI and Pusey P N 1992 Superlattice formation in binary mixtures of hard-sphere colloids Phys. Rev. Lett. 68 3801-4... 

For discotic molecules with long alkyl side chains, 2D assembly also often leads to mirror-symmetry-broken structures. In addition to steric hindrance and superlattice formation, the mechanism involves conformational mobility of the side chain [34], This has been shown for the Cu-phathlocyanine derivative CuPcOC8 on hopg using STM (Fig. 13). The C4v-symmetric molecule forms dense layers with interdigitated alkyl chains. This forces the molecules into a rotated structure [35,36]. 

Kanehara, M., Oumi, Y., Sano, T., and Teranishi, T. (2004) Syntheses of the novel acidic and basic ligands and superlattice formation from gold nanoparticles through interparticle acid-base interaction. Bulletin of the Chemical Society ofJapan, 77, 1589-1597. 

Figure 3.22. Unit cell representations of two varieties of AuCu superlattices. For the AuCu II superlattice, M refers to the length of repeat unit, and APB indicates the antiphase boundaries between adjacent periodic arrays. Republished with the permission of the International and American Associations for Dental Research, from Determination of the AuCu Superlattice Formation Region in Gold-Copper-Silver Ternary System , Uzuka, T. Kanzawa, Y. Yasuda, K. J. Dent. Res. 1981, 60, 883 permission conveyed through Copyright Clearance Center, Inc.

Preliminary photographs of a crystal may be taken in order to check for a cracked or twinned crystal, or for thermal diffuse scattering or superlattice formation. Some of the instruments for doing this are those that were historically used for data collection. It is now debated whether it is necessary to take such preliminary photographs, because the more sophisticated data-collecting devices, together with a high-speed computer, can provide much of the same information. The reader, however, may encounter these other methods, which are briefly described here. More details can be obtained from the listed references. 

Superlattice Formation General Conclusions. It has thus been experimentally established that the solute aluminium atoms at first keep as far away from each other as possible, and, as the concentration of the solid solution increases, they then take up positions (under suitable conditions), first at a distance of a. y/2, and then at a distance a, from each other, a being the lattice parameter. They are extremely unlikely to take up the possible positions separated only by the dis-... 

It may be noted, in conclusion, that superlattice formation provides a satisfactory explanation of the well-known but imperfectly-understood phase transformation in the... 

Yet another development of remarkable nanostmctured materials yields superlattices of nanosized objects. As there is no dear distinction between molecular crystals and superlattices formed from nanopartides, at this point reference will be made to structures composed of very similar (but most likely not exactly identical) nanopartides, namely colloidal partides in the size range 2 to 10 nm. Two excellent reviews by leading experts in the field were produced in 1998 and 2000 [19, 20], the titles of which contained the terms nanocrystal superlattices and close-packed nanociystal assemblies. These are in line with the above-outlined delimitation, although Collier et al. have also reported on molecular crystals (as above). The two reviews comprised approximately 100 pages with some 300 references, and summarized the state of the art at that time in exemplary fashion. The topics induded preparative aspects of the formation of monodisperse nanopartides of various compositions including metals, the superlattice formation itself with some theoretical background, covalent linking of nanocrystals (see below), and an appropriate description of the physical properties and characterization of the nanocrystal superlattices. 

Figure 4.1 (a) Schematic illustration of superlattice formation from colloidal solutions of 3.5 nm CdSe nanocrystals in toluene (b,c) Optical micrographs of the evolving nanocrystal superlattices after fast (b) and slow (c) nucleation. Reproduced with permission from Ref [24],... 

Hag] Hagiwara, M., Seki. J.-L, Suzuki, T., CsCl Type Superlattice Formation in V-Mn-Fe, Fe-V-Cr, and V -Mn-Cr Ternary Alloys (in Japanese), J. Jpn. Inst. Met, 39, 402-408 (1975) (Phase Diagram, Phase Relations, Thermodyn., Calculations, Experimental, 27)... 

Banga D, Stickney JL (2007) PbTe - PbSe superlattice formation by electrochemical atomic layer deposition. ECS Trans 6 (2, State-of-the-Art Program on Compound Semiconductors 46 (SOTAPOCS 46) and Processes at the Semiconduc-tor/Solution Interface 2) 439-449... 

Banga D, Kim Y-G, Stikney J (2011) PbSe/PbTe Superlattice Formation via Electrochemical Atomic Layer Depostion (E-ALD). J. Electrochem. Soc. 153 D99-D106. 

Synergistic Effect on Superlattice Formation in Self-Assembled Monolayers at Liquid-Solid Interfaces... 

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