Готові списки джерел за темами / Nanoparticle Superlattices

Добірка наукової літератури з теми "Nanoparticle Superlattices"

Автор: Grafiati

Опубліковано: 6 вересня 2023

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Статті в журналах з теми "Nanoparticle Superlattices"

Ross, Michael B., Jessie C. Ku, Martin G. Blaber, Chad A. Mirkin, and George C. Schatz. "Defect tolerance and the effect of structural inhomogeneity in plasmonic DNA-nanoparticle superlattices." Proceedings of the National Academy of Sciences 112, no. 33 (August 3, 2015): 10292–97. http://dx.doi.org/10.1073/pnas.1513058112.

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Bottom-up assemblies of plasmonic nanoparticles exhibit unique optical effects such as tunable reflection, optical cavity modes, and tunable photonic resonances. Here, we compare detailed simulations with experiment to explore the effect of structural inhomogeneity on the optical response in DNA-gold nanoparticle superlattices. In particular, we explore the effect of background environment, nanoparticle polydispersity (>10%), and variation in nanoparticle placement (∼5%). At volume fractions less than 20% Au, the optical response is insensitive to particle size, defects, and inhomogeneity in the superlattice. At elevated volume fractions (20% and 25%), structures incorporating different sized nanoparticles (10-, 20-, and 40-nm diameter) each exhibit distinct far-field extinction and near-field properties. These optical properties are most pronounced in lattices with larger particles, which at fixed volume fraction have greater plasmonic coupling than those with smaller particles. Moreover, the incorporation of experimentally informed inhomogeneity leads to variation in far-field extinction and inconsistent electric-field intensities throughout the lattice, demonstrating that volume fraction is not sufficient to describe the optical properties of such structures. These data have important implications for understanding the role of particle and lattice inhomogeneity in determining the properties of plasmonic nanoparticle lattices with deliberately designed optical properties.

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Liu, Jiaming, Rongjuan Liu, Zhijie Yang, and Jingjing Wei. "Folding of two-dimensional nanoparticle superlattices enabled by emulsion-confined supramolecular co-assembly." Chemical Communications 58, no. 23 (2022): 3819–22. http://dx.doi.org/10.1039/d2cc00330a.

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Prasad, B. L. V., C. M. Sorensen, and Kenneth J. Klabunde. "Gold nanoparticle superlattices." Chemical Society Reviews 37, no. 9 (2008): 1871. http://dx.doi.org/10.1039/b712175j.

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Radha, Boya, Andrew J. Senesi, Matthew N. O’Brien, Mary X. Wang, Evelyn Auyeung, Byeongdu Lee, and Chad A. Mirkin. "Reconstitutable Nanoparticle Superlattices." Nano Letters 14, no. 4 (March 18, 2014): 2162–67. http://dx.doi.org/10.1021/nl500473t.

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Park, Daniel J., Jessie C. Ku, Lin Sun, Clotilde M. Lethiec, Nathaniel P. Stern, George C. Schatz, and Chad A. Mirkin. "Directional emission from dye-functionalized plasmonic DNA superlattice microcavities." Proceedings of the National Academy of Sciences 114, no. 3 (January 4, 2017): 457–61. http://dx.doi.org/10.1073/pnas.1619802114.

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Three-dimensional plasmonic superlattice microcavities, made from programmable atom equivalents comprising gold nanoparticles functionalized with DNA, are used as a testbed to study directional light emission. DNA-guided nanoparticle colloidal crystallization allows for the formation of micrometer-scale single-crystal body-centered cubic gold nanoparticle superlattices, with dye molecules coupled to the DNA strands that link the particles together, in the form of a rhombic dodecahedron. Encapsulation in silica allows one to create robust architectures with the plasmonically active particles and dye molecules fixed in space. At the micrometer scale, the anisotropic rhombic dodecahedron crystal habit couples with photonic modes to give directional light emission. At the nanoscale, the interaction between the dye dipoles and surface plasmons can be finely tuned by coupling the dye molecules to specific sites of the DNA particle-linker strands, thereby modulating dye–nanoparticle distance (three different positions are studied). The ability to control dye position with subnanometer precision allows one to systematically tune plasmon–excition interaction strength and decay lifetime, the results of which have been supported by electrodynamics calculations that span length scales from nanometers to micrometers. The unique ability to control surface plasmon/exciton interactions within such superlattice microcavities will catalyze studies involving quantum optics, plasmon laser physics, strong coupling, and nonlinear phenomena.

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Кособукин, В. А. "Спектроскопия плазмон-экситонов в наноструктурах полупроводник-металл". Физика твердого тела 60, № 8 (2018): 1606. http://dx.doi.org/10.21883/ftt.2018.08.46256.18gr.

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AbstractThe results of the theory considering mixed plasmon-excitonic modes and their spectroscopy are presented. The plasmon-excitons are formed owing to strong Coulomb coupling between quasi-two-dimensional excitons of a quantum well and dipole plasmons of nanoparticles. The effective polarizability associated with a nanoparticle is calculated in a self-consistent approximation taking into account the local field determined by in-layer dipole plasmons and their image charges due to the excitonic polarization of a near quantum well. The spectra of elastic scattering and specular reflection of light are investigated in cases of a single silver nanoparticle and a monolayer of such particles situated in close proximity to a quantum well GaAs/AlGaAs. The optical spectra show a two-peak structure with a deep and narrow dip in the resonant range of plasmon-excitons. Propagation of plasmon-excitonic polaritons is discussed for periodic superlattices whose unit cell consists of a quantum well and a layer of metal nanoparticles. The superradiance regime originating in the Bragg diffraction of plasmon-excitonic polaritons by the superlattice is investigated. It is shown that the broad spectrum of plasmonic reflection depending on the number of unit cells in a superlattice also has a narrow dip at the exciton frequency.

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Podsiadlo, Paul, Galyna V. Krylova, Arnaud Demortière, and Elena V. Shevchenko. "Multicomponent periodic nanoparticle superlattices." Journal of Nanoparticle Research 13, no. 1 (December 31, 2010): 15–32. http://dx.doi.org/10.1007/s11051-010-0174-1.

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Nishida, Naoki, Edakkattuparambil S. Shibu, Hiroshi Yao, Tsugao Oonishi, Keisaku Kimura, and Thalappil Pradeep. "Fluorescent Gold Nanoparticle Superlattices." Advanced Materials 20, no. 24 (December 16, 2008): 4719–23. http://dx.doi.org/10.1002/adma.200800632.

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Shevchenko, E. V., J. Kortright, D. V. Talapin, S. Aloni, and A. P. Alivisatos. "Quasi-ternary Nanoparticle Superlattices Through Nanoparticle Design." Advanced Materials 19, no. 23 (December 3, 2007): 4183–88. http://dx.doi.org/10.1002/adma.200701470.

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Ouyang, Tianhao, Arash Akbari-Sharbaf, Jaewoo Park, Reg Bauld, Michael G. Cottam, and Giovanni Fanchini. "Self-assembled metallic nanoparticle superlattices on large-area graphene thin films: growth and evanescent waveguiding properties." RSC Advances 5, no. 120 (2015): 98814–21. http://dx.doi.org/10.1039/c5ra22052a.

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Дисертації з теми "Nanoparticle Superlattices"

Huesmann, Hannah [Verfasser]. "Artificial Nanoparticle-Polymer Superlattices / Hannah Huesmann." Mainz : Universitätsbibliothek der Johannes Gutenberg-Universität Mainz, 2021. http://d-nb.info/1229616853/34.

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Gilpin, Claire E. "Fabrication and Electronic Studies of PbSe Nanoparticle Superlattices." Thesis, University of California, Irvine, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10117111.

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Current global energy usage is largely dependent on non-renewable resources such as fossil fuels. Research is expanding into alternative, renewable energy sources such as solar energy. Of specific focus is research into the use of metal chalcoginide semiconductor nanoparticles as a cost-efficient platform for future use in solar applications. These semiconductor nanoparticles have size-dependent electronic band gaps within the solar spectrum and can be deposited into thin films from colloidal solutions. To date, most electronic studies have focused on thin films with disordered morphologies, where the dominant inter-nanoparticle charge transport mechanism is hopping. Highly spatially ordered metal chalcoginide nanoparticle films may have the ability to form extended Bloch states, thereby resulting in more efficient charge transport. This work focuses on fabricating both highly spatially ordered and highly disordered PbSe nanoparticle thin films to compare their electronic properties and elucidate charge transport mechanisms.

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Stoeva, Savka Ilieva. "Novel synthetic methods, superlattice formation and nanomachining of gold nanoparticles /." Search for this dissertation online, 2003. http://wwwlib.umi.com/cr/ksu/main.

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Hajiw, Stéphanie. "Des interactions entre nanoparticules d’or hydrophobes à leur auto-assemblage." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS080/document.

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Comme de nombreux colloïdes, des nanoparticules métalliques recouvertes de ligands en suspension s’organisent au-delà d’une fraction volumique seuil et forment ce que l’on appelle un « supracristal ». Ce sont ainsi des systèmes modèles, déjà largement étudiés à partir de suspensions dans des solvants volatils, qui permettent de mieux comprendre l’auto-assemblage de sphères déformables. Les interactions qui conduisent à l’auto-assemblage sont couramment décrites par une compétition entre une attraction de van der Waals entre les cœurs métalliques et une répulsion entre les ligands qui va dépendre de l’affinité entre les ligands et le solvant. Un effet du solvant a déjà été observé sur l’auto-organisation de nano-objets. En mesurant par diffusion de rayons X aux petits angles le facteur de structure de suspensions de nanoparticules d’or greffées, j’ai pu sonder de façon systématique les interactions entre des nanoparticules en suspension avec plusieurs tailles de cœur, des ligands alcane-thiols de longueur différente et dans différents solvants à la fois volatils et non volatils. J’ai ainsi pu mettre en évidence une interaction attractive inattendue dans des alcanes linéaires flexibles et dont l’intensité augmente avec la longueur de l’alcane. Pour corréler les interactions entre particules à leur diagramme de phase, j’ai suivi le processus de cristallisation dans des suspensions en solvant volatil ou partiellement volatil ainsi qu’en émulsion, techniques qui permettent d’augmenter lentement la concentration en nanoparticules. Les interactions attractives induites par le solvant contribuent ainsi à la formation de supracristaux à de très faibles fractions volumiques. A de fortes concentrations, la structure des supracristaux ne dépend pas du solvant utilisé mais, à forte densité de greffage, du rapport R entre la longueur des ligands et le diamètre du cœur d’or. Pour un rapport R voisin de 0.7, la structure finale observée est cubique centrée, la structure à concentration intermédiaire étant cubique à faces centrées. Pour un rapport R deux fois plus petit, une structure originale a été mise en évidence. Il s’agit d’une structure hexagonale de grand paramètre de maille, analysée comme une phase de Frank et Kasper de type MgZn2 ou C14. C’est la première fois qu’une telle phase à empilement local tétraédrique est observée dans un système de sphères monodisperses molles. L’existence de cette phase ainsi que le rôle du rapport R a pu être interprétée en estimant quantitativement la compétition entre l’attraction de van der Waals forte et l’entropie des ligands
As many colloids, metallic nanoparticles grafted with hydrophobic ligands self-assemble above a volume fraction threshold and thus build superlattices. These model systems, which are widely studied when suspended in volatile oils, enable a better understanding of soft spheres self-assembly.Interactions which lead to self-assembly are commonly described by the combination of van der Waals attraction with interaction between the ligand shells. The shell behavior is controlled by the ligand affinity with the solvent. An effect of the solvent on the self-assembly of nanoparticles has already been observed. Using a small angle X-ray scattering, I measured, through the structure factor, the interactions between gold nanoparticles grafted with alkanethiols in different oils, at various concentrations, for different lengths of ligands and core diameters. I noticed an attractive interaction when using flexible linear alkanes as solvent. It has also been shown that the attraction intensity increases with the solvent length.In order to correlate the interactions between particles to their phase diagram, I studied the crystallization process by concentrating nanoparticles using evaporation in capillaries or Ostwald ripening in emulsions. I showed that attractive interactions induced by the solvent lead to superlattices formation at very low volume fractions.At high concentrations, the superlattice structure depends on the ratio of the ligand length over the gold core diameter. For a ratio around 0.7, the final structure observed is body centered cubic, whereas at lower concentration, it is face centered cubic. When this ratio is halved, an unexpected structure is observed. It is a hexagonal structure with a large lattice parameter. It has been analyzed as a Frank and Kasper’s phase named MgZn2 or C14. It is the first time that this topologically close-packed structure is observed for monodisperse soft spheres. The existence of this phase and the role of the ratio R have been interpreted by considering quantitatively the competition between ligands entropy and the strong van der Waals attraction

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CASARIN, BARBARA. "A Structural and Optical Insight on Ge-Sb-Te based Nano-composites." Doctoral thesis, Università degli Studi di Trieste, 2019. http://hdl.handle.net/11368/2936428.

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Electronic memory and computing devices currently rules our digital lives, creating and consuming more than 10^21 bytes of data per year. This amount is expected to grow exponentially, questing for a so-called “hardware revolution”. Bit size-reduction governed the development of solid-state-memory and semiconductor technologies in the last decades. Yet, the innovative concept of an “universal memory” emerged for transcending the size-node. Indeed, this novel system combines high-speed computation and high-density storage skills. Memory devices based on Phase-Change Materials (PCMs) may serve to the scope, defying to scale reduction and both having a competitive erase/read speed with respect to the primary memory systems -as Static/Dynamic Random Access Memory (SRAM, DRAM)- and the large capacity of non-volatile secondary/tertiary storage systems -as Solid State Disk (SSD), Hard Disk Drive (HDD), Digital Video Disc (DVD). The appeal of Phase-Change Materials arises from their ability to rapidly and reversibly switch between the amorphous and crystalline states, via optical or electrical pulses. Interestingly, the two structural phases own significantly different physical properties, in particular in terms of reflectivity and conductivity. Many binary or ternary compounds display phase-change features, still Ge-Sb-Te (GST) alloys are the prominent members of this class of materials and are largely employed in industry. However, the main drawback is the PCMs relatively high operation power consumption, in the form of energy required for the phase transformation and of energy dissipation through -primarily- thermal diffusion. This thesis follows a GST dimensional strategy for power optimization -while maintaining advanced performances- for future integration in novel memory devices. The followed approach includes the case of 2-D highly-textured superlattice structures -of alternately deposited GeTe bilayers and Sb2Te3 quintuple layers- and of 0-D Ge2Sb2Te5 nanoparticles. Chapter 1 reviews the state-of-the-art of Phase-Change Materials, that stimulated the research questions addressed in the present work. Extended X-Ray Absorption Spectroscopy (EXAFS) -briefly presented in the first part of Chapter 2- is a powerful experimental tool for investigating a material’s atomic structure. As described in Chapter 3, one of the two allotrope crystalline phases of (GeTe)-(Sb2Te3) superlattices is revealed in details via EXAFS measurements performed at the Ge and Sb K-edges. The emerged structural picture is commented in light of the proposed models in literature, advising a power-saving yet over-simplified switching process occurring in the superlattice structure. Chapter 4 tackles the problem of power consumption by experimentally demonstrating the energy boost on the optical phase-change process occurring in 0-D Ge2Sb2Te5 nanoparticles. Here, a stable but reversible transition from the crystalline to the amorphous state of nanoparticles is induced with a single low-fluence femtosecond laser pulse. Thermodynamic, optical and structural considerations corroborate the experimental evidence. The laser source together with the setup used for the optical measurements are described in the second part of Chapter 2. The optical arrangement -conceived for time-resolved measurements- led to follow also the relaxation pathways of photo-excited nanoparticles below the threshold fluence for permanent amorphization. The results of this study are unveiled in Chapter 5. The ultrafast dynamics are compared to theoretical simulation and modelled with a phenomenological rate equation. Remarks on the resulting time-scales and the underlying interaction mechanisms -questioning the nature of the resonant bonding- close the Chapter.

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Smetana, Alexander B. "Gram quantities of silver and alloy nanoparticles : synthesisthrough digestive ripening and the solvated metal atom dispersion(SMAD) method: antimicrobial properties, superlatteic[superlattice] selfassembly,and optical properties." Manhattan, Kan. : Kansas State University, 2006. http://hdl.handle.net/2097/160.

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Kamali-Moghaddam, Saeed. "3d Transition Metals Studied by Mössbauer Spectroscopy." Doctoral thesis, Uppsala universitet, Fysik III, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6163.

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Layered crystals with magnetic elements as Co and Fe have been studied. In TlCo2Se2, where Co atoms in one sheet are separated by Tl and Se from the next Co sheet, magnetic interaction within and between the sheets have been studied. Samples doped with 4% 57Fe replaced Co, show a magnetic spiral character with hyperfine fields in a flower shape in the ab-plane. The magnetic moment of 0.46 μB per Co atom derived from the average field is in good agreement with the result from neutron diffraction. In TlCu1.73Fe0.27Se2 the easy axis of magnetisation is the c-axis. The magnetic moment calculated from the Mössbauer data and SQUID magnetrometry is 0.97 μB per Fe atom with TC = 55(5) K. Multilayers of different elements have been studied. The effect of vanadium atoms on iron atoms at the interface of FeNi/V multilayers has been determined and the intermixing at the interface has been calculated to be 2-3 monolayers. For FeNi/Co 1/1 monolayer the magnetic hyperfine field (Bhf) is 45° out-of-plane, while for superlattices containing 2 to 5 monolayers it is in the plane. An study on Fe/Co superlattice were done by experimental, theoretical and simulational methods. The Bhf is highest for the Fe at the second layer next to the interface and gets the bulk value in the centre of thicker Fe layers. Studied magnetic nanoparticles coated with a lipid bilayer (magnetoliposomes) are found to have the magnetite structure but being non-stoichiometric as a result of the manufacturing process. The composition was approximately 32% γ-Fe2O3 and 68% Fe3O4. The oxidation evolution and its effect on magnetic properties of Fe clusters were also studied by means of different techniques. The extraction and insertion mechanism of lithium in the cathode material Li2FeSiO4 has been monitored by in situ x-ray diffraction and Mössbauer spectroscopy during the first two cycles. The relative amount of Fe+3/ Fe+2 at each end state was in good agreement with the results obtained from electrochemical measurements. A possible explanation to the observed lowering of the potential plateau from 3.10 to 2.80 V occurring during the first cycle, involves a structural rearrangement process in which some of the Li ions and the Fe ions are interchanged. The behaviour of small amounts of Fe in brass is investigated using Mössbauer spectroscopy. It was shown that a heat treatment can increase the amount of the precipitates of γ-Fe and ~650° C is the optimal treatment for having the highest amount of this phase.

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Smetana, Alexander B. "Gram quantities of silver and alloy nanoparticles: synthesis through digestive ripening and the solvated metal atom dispersion (SMAD) method: antimicrobial properties, superlatteic[i.e. super lattice] selfassembly, and optical properties." Diss., Kansas State University, 2006. http://hdl.handle.net/2097/160.

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Doctor of Philosophy
Department of Chemistry
Kenneth J. Klabunde
This is an account of the synthesis of several drastically different forms of silver nanoparticles: Bare metal nanoparticles, dry nanoparticulate powders, aqueous soluble particles, and organic ligand coated monodisperse silver nanoparticles were all produced. The synthetic method was adapted from previous studies on gold nanoparticles and investigated to understand the optimal conditions for silver nanoparticle synthesis. Also the procedure for refinement of the nanoparticles was studied and applied to the formation of alloy nanoparticles. This extraordinary procedure produces beautifully colored colloids of spherical metal nanoparticles of the highest quality which under suitable conditions self-assemble into extensive three dimensional superlattice structures. The silver nanoparticle products were later tested against several biological pathogens to find dramatic increases in antimicrobial potency in comparison to commercially available silver preparations.

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Song, Qing. "Size and Shape Controlled Synthesis and Superparamagnetic Properties of Spinel Ferrites Nanocrystals." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7645.

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Size and Shape Controlled Synthesis and Superparamagnetic Properties of Spinel Ferrites Nanocrystals Qing Song 216 pages Directed by Dr. Z. John Zhang The correlationship between magnetic properties and magnetic couplings is established through the investigations of various cubic spinel ferrite nanocrystals. The results of this thesis contribute to the knowledge of size and shape controlled synthesis of various spinel ferrites and core shell architectured nanocrystals as well as the nanomagnetism in spinel ferrites by systematically investigating the effects of spin orbital coupling, magnetocrystalline anisotropy, exchange coupling, shape and surface anisotropy upon superparamagnetic properties of spinel ferrite nanocrystals. A general synthetic method is developed for size and shape control of metal oxide nanocrystals. The size and shape dependent superparamagnetic properties are discussed. The relationship between spin orbital coupling and magnetocrystalline anisotropy is studied comparatively on variable sizes of spherical CoFe2O4 and Fe3O4 nanocrystals. It also addresses the effect of exchange coupling between magnetic hard phase and soft phase upon magnetic properties in core shell structured spinel ferrite nanocrystals. The role of anisotropic shapes of nanocrystals upon self assembled orientation ordered superstructures are investigated. The effect of thermal stability of molecular precursors upon size controlled synthesis of MnFe2O4 nanocrystals and the size dependent superparamagnetic properties are described.

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Zschintzsch-Dias, Manuel. "Self organized formation of Ge nanocrystals in multilayers." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-86838.

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The aim of this work is to create a process which allows the tailored growth of Ge nanocrystals for use in photovoltic applications. The multilayer systems used here provide a reliable method to control the Ge nanocrystal size after phase separation. In this thesis, the deposition of GeOx/SiO2 and Ge:SiOx~ 2/SiO2 multilayers via reactive dc magnetron sputtering and the self-ordered Ge nanocrystal formation within the GeOx and Ge:SiOx~ 2 sublayers during subsequent annealing is investigated. Mostly the focus of this work is on the determination of the proper deposition conditions for tuning the composition of the systems investigated. For the GeOx/SiO2 multilayers this involves changing the GeOx composition between elemental Ge (x = 0) and GeO2 (x = 2), whereas for the Ge:SiOx~ 2/SiO2 multilayers this involves changing the stoichiometry of the Ge:SiOx~ 2 sublayers in the vicinity of stochiometric silica (x = 2). The deposition conditions are controlled by the variation of the deposition rate, the deposition temperature and the oxygen partial pressure. A convenient process window has been found which allows the sequential deposition of GeOx/SiO2 or Ge:SiOx ~2/SiO2 without changing the oxygen partial pressure during deposition. For stoichiometry determination Rutherford back-scattering spectrometry has been applied extensively. The phase separation in the spatially confined GeOx and Ge:SiOx ~2 sublayers was investigated by X-ray absorption spectroscopy at the Ge K-edge. The Ge sub-oxides content of the as-deposited multilayers diminishes with increasing annealing temperature, showing complete phase separation at approximately 450° C for both systems (using inert N2 at ambient pressure). With the use of chemical reducing H2 in the annealing atmosphere, the temperature regime where the GeOx phase separation occurs is lowered by approximately 100 °C. At temperatures above 400° C the sublayer composition, and thus the density of the Ge nanocrystals, can be altered by making use of the reduction of GeO2 by H2. The Ge nanocrystal formation after subsequent annealing was investigated with X-ray scattering, Raman spectroscopy and electron microscopy. By these methods the existence of 2 - 5 nm Ge nanocrystals at annealing temperatures of 550 (GeOx) - 700° C (Ge:SiOx ~2) has been confirmed which is within the multilayer stability range. The technique used allows the production of extended multilayer stacks (50 periods ~ 300 nm) with very smooth interfaces (roughness ~ 0.5 nm). Thus it was possible to produce Ge nanocrystal layers with ultra-thin SiO2 separation layers (thickness ~ 1 nm) which offers interesting possibilities for charge transport via direct tunneling.

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Книги з теми "Nanoparticle Superlattices"

Blunt, MO, A. Stannard, E. Pauliac-Vaujour, CP Martin, Ioan Vancea, Milovan Suvakov, Uwe Thiele, Bosiljka Tadic, and P. Moriarty. Patterns and pathways in nanoparticle self-organization. Edited by A. V. Narlikar and Y. Y. Fu. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199533046.013.8.

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This article reviews relatively recent forms of self-assembly and self-organization that have demonstrated particular potential for the assembly of nanostructured matter, namely biorecognition and solvent-mediated dynamics. It first considers the key features of self-assembled and self-organized nanoparticle arrays, focusing on the self-assembly of nanoparticle superlattices, the use of biorecognition for nanoparticle assembly, and self-organizing nanoparticles. It then describes the mechanisms and pathways for charge transport in nanoparticle assemblies, with particular emphasis on the relationship between the current–voltage characteristics and the topology of the lattice. It also discusses single-electron conduction in nanoparticle films as well as pattern formation and self-organization in dewetting nanofluids.

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Fu, Huaxiang. Unusual properties of nanoscale ferroelectrics. Edited by A. V. Narlikar and Y. Y. Fu. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199533053.013.19.

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This article describes the unusual properties of nanoscale ferroelectrics (FE), including widely tunable polarization and improved properties in strained ferroelectric thin films; polarization enhancement in superlattices; polarization saturation in ferroelectric thin films under very large inplane strains; occurrence of ferroelectric phase transitions in one-dimensional wires; existence of the toroidal structural phase in ferroelectric nanoparticles; and the symmetry-broken phase-transition path when one transforms a vortex phase into a polarization phase. The article first considers some of the critical questions on low-dimensional ferroelectricity before discussing the theoretical approaches used to determine the properties of ferroelectric nanostructures. It also looks at 2D ferroelectric structures such as surfaces, superlattices and thin films, along with 1D ferroelectric nanowires and ferroelectric nanoparticles.

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Частини книг з теми "Nanoparticle Superlattices"

Thomas, Steffi S., and Fabian Meder. "Nanoparticle Superlattices." In 21st Century Nanoscience – A Handbook, 3–1. Boca Raton, Florida : CRC Press, [2020]: CRC Press, 2020. http://dx.doi.org/10.1201/9780429347313-3.

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Petit, Christophe, Caroline Salzemann, and Arnaud Demortiere. "Platinum and Palladium Nanocrystals: Soft Chemistry Approach to Shape Control from Individual Particles to Their Self-Assembled Superlattices." In Complex-Shaped Metal Nanoparticles, 305–37. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2012. http://dx.doi.org/10.1002/9783527652570.ch9.

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Pileni, M. P. "Self-Organization of Spherical Nanoparticles in Two- and Three-Dimensinal Superlattices." In ACS Symposium Series, 29–40. Washington, DC: American Chemical Society, 1997. http://dx.doi.org/10.1021/bk-1997-0679.ch004.

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Radha, Boya, Senesi Andrew J., Matthew N. O’Brien, Mary X. Wang, Evelyn Auyeung, Byeongdu Lee, and Chad A. Mirkina. "Reconstitutable Nanoparticle Superlattices*." In Spherical Nucleic Acids, 1055–68. Jenny Stanford Publishing, 2020. http://dx.doi.org/10.1201/9781003056706-61.

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Radha, Boya, Andrew J. Senesi, Matthew N. O’Brien, Mary X. Wang, Evelyn Auyeung, Byeongdu Lee, and Chad A. Mirkin. "Reconstitutable Nanoparticle Superlattices*." In Spherical Nucleic Acids, 1055–68. Jenny Stanford Publishing, 2020. http://dx.doi.org/10.1201/9781003056706-9.

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Shevchenko, Elena V. "Multicomponent nanoparticle superlattices." In Reference Module in Materials Science and Materials Engineering. Elsevier, 2022. http://dx.doi.org/10.1016/b978-0-12-822425-0.00112-3.

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Macfarlane, Robert J., Matthew R. Jones, Byeongdu Lee, Evelyn Auyeung, and Chad A. Mirkin. "Topotactic Interconversion of Nanoparticle Superlattices*." In Spherical Nucleic Acids, 1081–92. Jenny Stanford Publishing, 2020. http://dx.doi.org/10.1201/9781003056706-11.

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Тези доповідей конференцій з теми "Nanoparticle Superlattices"

Gillet, Jean-Numa, Sebastian Volz, and Yann Chalopin. "Atomic Scale Three-Dimensional Phononic Crystals With Very Low Thermal Conductivities." In ASME 2008 First International Conference on Micro/Nanoscale Heat Transfer. ASMEDC, 2008. http://dx.doi.org/10.1115/mnht2008-52111.

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Superlattices have been used to design thermoelectric materials with ultra-low thermal conductivities. Indeed, the thermoelectric figure of merit ZT varies as the inverse of the material thermal conductivity. However, the design of a thermoelectric material with ZT superior to the alloy limit usually fails with the superlattices because of two major drawbacks: First, a lattice mismatch can occur between the different layers of a superlattice as in a Si/Ge superlattice. This leads to the formation of defects and dislocations, which reduces the electrical conductivity and therefore avoids the increase of ZT compared to the alloy limit. On the other hand, the superlattices only affect heat transfer in one direction. To cancel heat conduction in the three spatial directions, we propose atomic-scale three-dimensional (3D) phononic crystals. Because the lattice constant of our phononic crystal is of the order of some nanometers, we obtain phonon confinement in the THz range and a nanomaterial with a very low thermal conductivity. This is not possible with the usual phononic crystals, which show band gaps in the sub-MHz range owing to their large lattice constant of the order of 1 mm. A period of our atomic-scale 3D phononic crystal is composed of a given number of diamond-like silicon cells forming a supercell. A periodic Si/Ge heterostructure is obtained since we substitute at each supercell center the Si atoms in a smaller number of cells by Ge atoms. The Ge atoms in the cells located at each supercell center form a box-like nanoparticle with a size that can be varied to obtain different atomic configurations of our nanomaterial. We also propose another design for our phononic crystal where we introduce a small number of diamond-like silicon cells at the center of a periodic supercell of diamond-like germanium cells. In this second design, we form box-like nanoparticles of Si atoms in a germanium matrix instead of boxlike nanoparticles of Ge atoms in a silicon matrix in the first design. With the dispersion curves computed by lattice dynamics and a general equation, we obtain the thermal conductivities of several atomic configurations of our phononic crystal. Compared to a bulk material, the thermal conductivity can be reduced by at least one order of magnitude in our phononic crystal. This reduction is only due to the phonon group velocities, and we expect a further decrease owing to the diminution of the phonon mean free path in our phononic crystal.

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Aydin, Koray. "Dynamic optical metasurfaces and self-assembled metamaterials using plasmonic nanoparticle superlattices." In Quantum Sensing and Nano Electronics and Photonics XIX, edited by Manijeh Razeghi, Giti A. Khodaparast, and Miriam S. Vitiello. SPIE, 2023. http://dx.doi.org/10.1117/12.2647915.

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Gillet, Jean-Numa, Yann Chalopin, and Sebastian Volz. "Atomic-Scale Three-Dimensional Phononic Crystals With a Lower Thermal Conductivity Than the Einstein Limit of Bulk Silicon." In ASME 2008 Heat Transfer Summer Conference collocated with the Fluids Engineering, Energy Sustainability, and 3rd Energy Nanotechnology Conferences. ASMEDC, 2008. http://dx.doi.org/10.1115/ht2008-56403.

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Extensive research about superlattices with a very low thermal conductivity was performed to design thermoelectric materials. Indeed, the thermoelectric figure of merit ZT varies with the inverse of the thermal conductivity but is directly proportional to the power factor. Unfortunately, as nanowires, superlattices reduce heat transfer in only one main direction. Moreover, they often show dislocations owing to lattice mismatches. Therefore, fabrication of nanomaterials with a ZT larger than the alloy limit usually fails with the superlattices. Self-assembly is a major epitaxial technology to fabricate ultradense arrays of germaniums quantum dots (QD) in a silicon matrix for many promising electronic and photonic applications as quantum computing. We theoretically demonstrate that high-density three-dimensional (3-D) periodic arrays of small self-assembled Ge nanoparticles (i.e. the QDs), with a size of some nanometers, in Si can show a very low thermal conductivity in the three spatial directions. This property can be considered to design thermoelectric devices, which are compatible with the complementary metal-oxide-semiconductor (CMOS) technologies. To obtain a computationally manageable model of these nanomaterials, we simulate their thermal behavior with atomic-scale 3-D phononic crystals. A phononic-crystal period (supercell) consists of diamond-like Si cells. At each supercell center, we substitute Si atoms by Ge atoms in a given number of cells to form a box-like Ge nanoparticle. The phononic-crystal dispersion curves, which are computed by classical lattice dynamics, are flat compared to those of bulk Si. In an example phononic crystal, the thermal conductivity can be reduced below the value of only 0.95 W/mK or by a factor of at least 165 compared to bulk silicon at 300 K. Close to the melting point of silicon, we obtain a larger decrease of the thermal conductivity below the value of 0.5 W/mK, which is twice smaller than the classical Einstein Limit of single crystalline Si. In this paper, we use an incoherent-scattering approach for the nanoparticles. Therefore, we expect an even larger decrease of the phononic-crystal thermal conductivity when multiple-scattering effects, as multiple reflections and diffusions of the phonons between the Ge nanoparticles, will be considered in a more realistic model. As a consequence of our simulations, a large ZT could be achieved in 3-D ultradense self-assembled Ge nanoparticle arrays in Si. Indeed, these nanomaterials with a very small thermal conductivity are crystalline semiconductors with a power factor that can be optimized by doping using CMOS-compatible technologies, which is not possible with other recently-proposed nanomaterials.

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Gillet, Jean-Numa, Yann Chalopin, and Sebastian Volz. "Thermal Modeling of Atomic-Scale Three-Dimensional Phononic Crystals for Thermoelectric Applications." In ASME 2008 3rd Energy Nanotechnology International Conference collocated with the Heat Transfer, Fluids Engineering, and Energy Sustainability Conferences. ASMEDC, 2008. http://dx.doi.org/10.1115/enic2008-53052.

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Extensive research on semiconducting superlattices with a very low thermal conductivity was performed to fabricate thermoelectric materials. However, as nanowires, superlattices affect heat transfer in only one main direction, and often show dislocations owing to lattice mismatches when they are made up of a periodic repetition of two materials with different lattice constants. This reduces their electrical conductivity. Therefore it is challenging to obtain a thermoelectric figure of merit ZT superior to unity with the superlattices. Self-assembly with lithographic patterning and/or liquid precursors is a major epitaxial technology to fabricate ultradense arrays of germaniums quantum dots (QDs) in silicon for many promising electronic and photonic applications as quantum computing where accurate QD positioning and low degree of dislocations are required. We theoretically demonstrate that high-density three-dimensional (3-D) arrays of self-assembled Ge nanoparticles, with a size of some nanometers, in Si can also show a very low thermal conductivity in the three spatial directions. This property can now be considered to design new thermoelectric devices, which are compatible with new complementary metal-oxide-semiconductor (CMOS) processes. To obtain a computationally manageable model of these nanomaterials, we simulate their thermal behavior with atomic-scale 3-D phononic crystals. A phononic-crystal period or supercell consists of diamond-like Si cells. At each supercell center, we substitute Si atoms by Ge atoms in a given number of cells to form a box-like nanoparticle. According to our model, in an example 3-D phononic crystal, the thermal conductivity can be reduced to a value lower than only 0.2 W/mK or by a factor of at least 750 compared to bulk Si at 300 K. This value is five times smaller than the Einstein Limit of single-crystalline bulk Si. We considered the flat dispersion curves computed by lattice dynamics to obtain this huge decrease. However, we did not consider multiple-scattering effects as multiple reflections and diffusions of the phonons between the Ge nanoparticles. We expect a larger decrease of the real thermal conductivity owing to the reduction of the phonon mean free paths from these collective effects. We hope to obtain a large ZT in these self-assembled Ge nanoparticle arrays in Si. Indeed, they are crystalline with an electrical conductivity that can be also increased by doping using CMOS processes, which is not possible with other recently proposed materials.

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Gillet, Jean-Numa, and Sebastian Volz. "Atomic-Scale Three-Dimensional Phononic Crystals With a Large Thermoelectric Figure of Merit." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-68381.

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The design of thermoelectric materials led to extensive research on superlattices with a low thermal conductivity. Indeed, the thermoelectric figure of merit ZT varies with the inverse of the thermal conductivity but is directly proportional to the power factor. Unfortunately, as nanowires, superlattices cancel heat conduction in only one main direction. Moreover they often show dislocations owing to lattice mismatches, which reduces their electrical conductivity and avoids a ZT larger than unity. Self-assembly is a major epitaxial technology to design ultradense arrays of germanium quantum dots (QDs) in silicon for many promising electronic and photonic applications as quantum computing. Accurate positioning of the self-assembled QD can now be achieved with few dislocations. We theoretically demonstrate that high-density three-dimensional (3-D) arrays of self-assembled Ge QDs, with a size of only some nanometers, in a Si matrix can also show an ultra-low thermal conductivity in the three spatial directions. This property can be considered to design new CMOS-compatible thermoelectric devices. To obtain a realistic and computationally-manageable model of these nanomaterials, we simulate their thermal behavior with atomic-scale 3-D phononic crystals. A phononic-crystal period (supercell) consists of diamond-like Si cells. At each supercell center, we substitute Si atoms by Ge atoms to form a box-like nanoparticle. Since this phononic crystal is periodic, we compute its phonon dispersion curves by classical lattice dynamics. Non-periodicities can be introduced with statistical distributions. From the flat dispersion curves, we obtain very small group velocities; this reduces the thermal conductivity in our phononic crystal compared to bulk Si. However, owing to the wave-particle duality at very small scales in quantum mechanics, another reduction arises from multiple scattering of the particle-like phonons in nanoparticle clusters. At room temperature, the thermal conductivity in an example phononic crystal can be reduced by a factor of at least 165 compared to bulk Si or below 0.95 W/mK. This value, which is lower than the classical Einstein limit of single crystalline Si, is an upper limit of the thermal conductivity since we use an incoherent-scattering approach for the nanoparticles. Because of its very low thermal conductivity, we hope to obtain a much larger ZT than unity in our atomic-scale 3-D phononic crystal. Indeed, this silicon-based nanomaterial is crystalline with a power factor that can be optimized by doping using CMOS-compatible processes. Future research on the phononic-crystal electrical conductivity has to be performed in order to compute the full ZT with a good accuracy.

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LIN, J., W. L. ZHOU, and C. J. O'CONNOR. "SYNTHESIS AND SELF-ORGANIZATION OF GOLD NANOPARTICLES INTO SUPERLATTICES FROM CTAB REVERSE MICELLES." In Proceedings of the International Symposium. WORLD SCIENTIFIC, 2000. http://dx.doi.org/10.1142/9789812793805_0051.

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Kruglenko, Ivanna, Sergii Kravchenko, Petro Kruglenko, Julia Burlachenko, Iryna Krishchenko, Edward Manoilov, and Boris Snopok. "Advanced Quartz Microbalance Sensors for Gas-Phase Applications: Effect of Adsorbate on Shear Bond Stiffness between Physical Transducer and Superlattice of Latex Nanoparticles." In ECSA-9. Basel Switzerland: MDPI, 2022. http://dx.doi.org/10.3390/ecsa-9-13204.

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Ren, Z. F. "Nano Materials and Physics." In ASME 4th Integrated Nanosystems Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/nano2005-87045.

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Aligning carbon nanotubes in any way desired is very important for many fundamental and applied research projects. In this talk, I will first discuss how to grow them with controlled diameter, length, spacing, and periodicity using catalyst prepared by magnetron sputtering, electron beam (e-beam) lithography, electrochemical deposition, and nanosphere self-assembly. Then I will present our results of field emission property of both the aligned carbon nanotubes grown on flat substrates and random carbon nanotubes grown on carbon cloth. For the aligned carbon nanotubes arrays, I will present the preliminary results of using them as photonic band gap crystals and nanoantennae. As an alternative material of carbon nanotubes, ZnO nanowires have been grown in both aligned fashion on flat substrates and random fashion on carbon cloth. Using these ZnO nanowires, good field emission properties were observed. Furthermore, I will present our recent studies on the electrical breakdown and transport properties of a single suspended nanotube grown on carbon cloth by a scanning electron microscope probe incorporated into a high resolution transmission electron microscope. As part of the potential applications, I will also discuss our recent success on molecules delivery into cells using carbon nanotubes. Finally I will talk about our most recent endeavor on achieving thermoelectric figure-of-merit (ZT) higher than 2 using our unique nanocomposite approach. Plasma-enhanced chemical vapor deposition (PECVD) was discovered by my group in 1998 to be able to grow aligned carbon nanotubes [1]. Catalyst film was first deposited by magnetron sputtering. According to the thickness of the catalytic film, aligned carbon nanotubes were grown with different diameters and spacing, and different length depending the growth time. However, the two major drawbacks are 1) that the location of where the nantoube grows can not be controlled, 2) that the spacing between the nanotubes can not be varied too much. Therefore, we immediately explored to grow aligned carbon nanotubes with the location and spacing controls using e-beam lithography [2]. Unfortunately the cost is so high that the e-beam is not suited for large scale commercialization that requires only an average site density control not the exactly location, for example, electron source. It is the cost issue that made us to develop electrochemical deposition to make catalyst dots that can be separated more than 10 micormeters between dots [3]. With such arrays, we tested many samples for field emission properties and found the optimal site density [4]. However, for applications that require the location controls, for example, photonic band gap crystals, electrochemical deposition can not be satisfactory. It is this kind of application that led us to develop the nanosphere self-assembly technique in large scale [5]. For field emission, we found that ZnO nanowires are good field emitters comparable to carbon nanotubes if they are grown with the right diameter and spacing. Here I will discuss the field emission properties of ZnO nanowires as an alternative material to carbon nanotubes [6]. Us a special kind of carbon nanotubes made by PECVD, we discovered a highly efficient molecular delivery technique, named nanotube spearing, based on the penetration of Ni-particle embedded nanotubes into cell membranes by magnetic field driving. DNA plasmids encoding the enhanced green fluorescent protein (EGFP) sequence were immobilized onto the nanotubes, and subsequently speared into targeted cells. We have achieved the unprecedented high transduction efficiency in Bal17 B-lymphoma, ex vivo B cells, and primary neurons with high viability. This technique may provide a powerful tool for high efficient gene transfer in a variety of cells, especially, the hard-to-transfect cells [7]. Conventional transport studies of multiwall carbon nanotubes (MWNTs) with only the outmost wall contacted to the electrodes via side-contact shows that a MWNT is a ballistic conductor with only the outmost wall carrying current. Here we show, by using end-contact in which every wall is contacted to the electrodes, that every wall is conducting, as evidenced by a significant amount of current drop when an innermost wall is broken at high-bias. Remarkably, the breakdown of each wall was initiated in the middle of the nanotube, not at the contacts, indicating diffusive electron transport. Using end-contact, we were able to probe the conductivity wall-by-wall and found that each wall is indeed either metallic, or semiconducting, or pseudogap-like. These findings not only reveal the intrinsic physical properties of MWNTs but also provide important guidance to MWNT-based electronic devices [8]. At the end of the talk, if time permits, I will talk about our ongoing effort on improving the figure-of-merit (ZT) of thermoelectric materials using a nanocomposite strategy to mimic the structure of the superlattice of PbTe/PbSe and Bi2Te3/Sb2Te3 hoping to reduce the thermal conductivity by a factor of 2–4 while maintaining the electrical conductivity. To make a close to 100% dense nanocomposite, we started with nanoparticles synthesis, then consolidation using both the traditional hot press and the direct current fast-heat, named plasma pressure compact, to preserve the nano size of the component particles. So far, we have seen thermal conductivity decrease by a factor of 2 in the systems of Si/Ge, PbeTe/PbSe, Bi2Te3/Sb2Te3, indicating the potential of improving ZT by a factor of 2.

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Звіти організацій з теми "Nanoparticle Superlattices"

Srivastava, Ishan, Brandon L. Peters, James Matthew Doyle Lane, Hongyou Fan, Gary S. Grest, and Michael K. Salerno. Mechanics of Gold Nanoparticle Superlattices at High Hydrostatic Pressure. Office of Scientific and Technical Information (OSTI), September 2018. http://dx.doi.org/10.2172/1476165.

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