Three-dimensional superlattices

Two-Dimensional and Three-Dimensional Superlattices Syntheses and Collective Physical Properties... 

Chapter 8 presents evidence on how the physical properties of colloidal crystals organized by self-assembly in two-dimensional and three-dimensional superlattices differ from those of the free nanoparticles in dispersion. 

Oonishi, T., Sato, S., Yao, H. and Kimura, K. (2007) Three-dimensional gold nanopartide superlattices Structures and optical absorption characteristics. Journal of Applied Physics, 101, 114314. 

Crystalline phases (truncated octahedra) of 5 nm silver particles, thiolate protected as well, have been detected by means of high-resolution transmission electron microscopy (HRTEM) [26-28]. Three-dimensional architectures of 5-6 nm thiolate-stabilized gold particles have also been described [29]. Several other reports on 3D superlattices of metal nanoparticles have become known during the last few years [30-33]. 

Lead nitrate complexed with EDTA and lead perchlorate and sodium sulphide have been used for PbS ECALE-deposition.158159 The films were cubic and highly (200) oriented, and AFM images showed the same cubic structure.158159 PbSe films were also cubic, and the band gap of a film after 50 deposition cycles was 8000cm-1.160 PbSe/PbTe superlattices, with 4.2-nm and 7.0-nm periods, have been grown by ECALE.161 The (111) reflection in the XRD pattern showed a first-order satellite peak and one second-order peak, indicating the formation of the superlattice. AFM images of the superlattice structure showed a small amount of three-dimensional growth.161... 

Talapin, D. V. Shevchenko, E. V. Kornowski, A. Gaponik, N. Haase, M. Rogach, A. L. Weller, H. 2001. A new approach to crystalhzation of CdSe nanoparticles into ordered three-dimensional superlattices. Adv. Mater. 13 1868-1871. 

Murray, C. B. Kagan, C. R. Bawendi, M. G. 1995. Self-organization of CdSe nanocrystallites into three-dimensional quantum dot superlattices. Science 270 1335-1338. 

Figure 1 2 1. The different types of 2.5 Lifshitz electronic topological transition (ETT) The upper panel shows the type (I) ETT where the chemical potential EF is tuned to a Van Hove singularity (vHs) at the bottom (or at the top) of a second band with the appearance (or disappearance) of a new detached Fermi surface region. The lower panel shows the type (II) ETT with the disruption (or formation) of a neck in a second Fermi surface where the chemical potential EF is tuned at a vHs associated with the gradual transformation of the second Fermi surface from a two-dimensional (2D) cylinder to a closed surface with three dimensional (3D) topology characteristics of a superlattice of metallic layers...

Luther, P. K., and Squire, J. M. (1980). Three-dimensional structure of the vertebrate muscle A-band. II. The myosin filament superlattice. / Mol. Biol. 141,... 

Luther, P. K., and Squire, J. M. (1980). Three-dimensional structure of the vertebrate muscle A-band. II. The myosin filament superlattice./. Mol. Biol. 141, 409-439. Luther, P. K., and Squire, J. M. (2002). Muscle Z-band ultrastructure Titin Z-repeats and Z-band periodicities do not match./. Mol. Biol. 319, 1157-1164. 

Redl, F. X., Cho, K. S., Murray, C. B. O Brien, S. Three-dimensional binary superlattices of magnetic nanocrystals and semiconductor quantum dots. Nature (London) 423, 968—971 (2003). 

In general, unlike for the perfect epitaxial structures of fully strained materials, for nitride heteroepitaxial layers it is essential to perform not a single scan for a symmetrical reflection, but a set of two- or even three-dimensional maps of symmetrical and asymmetrical reflections. Additionally, for some applications, an intense beam is needed and therefore low-resolution X-ray diffractometry can be sometimes a preferable technique to the commonly used high-resolution XRD. For example, if we examine a heterostructural nitride superlattice, low resolution diffractometry will give us a broader zeroth-order peak (information on the whole layer) but more satellite peaks (information on the sublayers). Therefore, multipurpose diffractometers with variable configurations are the most desirable in nitride research. 

Fig. 21.4 Temperature dependencies of normalized Raman intensities of TO2 (solid triangles) and TO4 (open triangles) phonons for (a) SLs [(BaTi03)2(SrTi03)4] x 40 and [(BaTi03)5(SrTi03)4] x 25 (b) SLs [(BaTi03)g(SrTi03)4] x 40 and [(BaTi03)8(SrTi03)4] x 10. The dash-dotted lines are fits to linear temperature dependence, (c) and (d) - three-dimensional phase-field model calculations of polarization as a function of temperature in the same superlattice...

Fig. 21.5 Tc dependence on layer thicknesses n and m in superlattices (BaTi03) / (SrTi03) j. Blue triangles and red circles are for m = 4 and m = 13, respectively. Open squares show the values obtained from variable temperature X-ray diffraction measurements. Solid lines are from the three-dimensional phase-field model calculations, dashed lines -simulations assuming a single domain in the BaTi03 layers. The dash-dotted line shows in bulk BaTi03 (After Li et al. [150])...

The way in which the nanocrystals organize themselves depends critically on the core diameter, the nature of the ligand, substrate and even the dispersive medium used [101]. Thiolized metal nanocrystals readily arrange into two-dimensional arrays on removal of the solvent [29]. Using suitable methods, they can also be put into one-dimensional organization in the form of strings or assembled in a stepwise fashion in a three-dimensional superlattice (see Figure 4.8). 

Fig. 4.15. Three-dimensional superlattices of 4.8 nm CdSe nanocrystals (a) along orientation (b) along <101) orientation (c) along orientation. High resolution...

The distance between metal ion clusters and the orientation of the clusters in zeolite cages depends on the zeolite hosts, and as a result the three-dimensional arrays can be described in different ways. They can be called cluster crystals or superlattices. The Na/ Na-Y cluster crystal formed by accommodation of one Na43+ cluster in each sodalite cage is written as in Equation (9.2) ... 

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