 |
|
University of Pennsylvania engineers discover natural 'workbench' for nanoscale construction
July 18, 2007PHILADELPHIA -- Engineers at the University of Pennsylvania have taken a step toward simplifying the creation of nanostructures by identifying the first inorganic material to phase separate with near-perfect order at the nanometer scale. The finding provides an atomically tuneable nanocomposite "workbench" that is cheap and easy to produce and provides a super-lattice foundation potentially suitable for building nanostructures.
The findings appear in the August issue of Nature Materials.
Alerted by an unusual diffraction effect of a common ceramic material, researchers used imaging to identify a two-phase structural pattern ideal as the first step towards nanodevice construction. Practical application of nanotechnology will rely upon engineering's ability to manipulate atoms and molecules into long-range order to produce materials with desired functionalities. The Penn findings provide a simpler method for the ordering of composite parts on the nanometer scale, which is integral to the incorporation of nano-objects such as particles and wires that make up nanodevices.
The material used in the Penn study is an ionically- conductive, crystalline ceramic (Nd2/3-xLi3x)TiO3 that engineers observed with transmission electron microscopy. The powdered perovskite exhibited two distinct patterns at the atomic scale with identical periodicity: a nanoscale chessboard pattern and a diamond pattern that indicated periodic separation into two phases within the structure. This spontaneous separation of phases could present a new foundation on which to build nanodevice technology. This material - made using standard and easily reproducible ceramic processing methods - represents the formation of a spontaneous microscopic surface controlled on the nanoscale with atomic precision.
Further study revealed that the separation of the structure into two distinct phases was a result of the oxide separating into lithium rich squares and lithium poor stripes. By varying the amount of lithium and neodymium, two ingredients in the ceramic powder, engineers controlled the length and spacing of the alternating phases, thereby tuning the workbench upon which nanodevices could be built.
On a larger-than-atomic scale, the research extends science's knowledge of the properties of a most common oxide structure type, currently used for superconducting materials, magnetoresistive materials and ferroelectrics.
"This study represents great potential for the use of standard ceramic processing methods for nanotechnology," said Peter K. Davies, chair of the Department of Materials Science and Engineering at Penn. "The phase separation occurs spontaneously, providing two phases whose dimensions both extend into the nanometer scale. This unique feature could lead to its application as a template for the assembly of nanostructures or molecular monolayers."
University of Pennsylvania
The material used in the Penn study is an ionically- conductive, crystalline ceramic (Nd2/3-xLi3x)TiO3 that engineers observed with transmission electron microscopy. The powdered perovskite exhibited two distinct patterns at the atomic scale with identical periodicity: a nanoscale chessboard pattern and a diamond pattern that indicated periodic separation into two phases within the structure. This spontaneous separation of phases could present a new foundation on which to build nanodevice technology. This material - made using standard and easily reproducible ceramic processing methods - represents the formation of a spontaneous microscopic surface controlled on the nanoscale with atomic precision.
Further study revealed that the separation of the structure into two distinct phases was a result of the oxide separating into lithium rich squares and lithium poor stripes. By varying the amount of lithium and neodymium, two ingredients in the ceramic powder, engineers controlled the length and spacing of the alternating phases, thereby tuning the workbench upon which nanodevices could be built.
On a larger-than-atomic scale, the research extends science's knowledge of the properties of a most common oxide structure type, currently used for superconducting materials, magnetoresistive materials and ferroelectrics.
"This study represents great potential for the use of standard ceramic processing methods for nanotechnology," said Peter K. Davies, chair of the Department of Materials Science and Engineering at Penn. "The phase separation occurs spontaneously, providing two phases whose dimensions both extend into the nanometer scale. This unique feature could lead to its application as a template for the assembly of nanostructures or molecular monolayers."
University of Pennsylvania
Nanostructures Current Events and Nanostructures News RSSLANL Roadrunner simulates nanoscale material failure
Very tiny wires, called nanowires, made from such metals as silver and gold, may play a crucial role as electrical or mechanical switches in the development of future-generation ultrasmall nanodevices.
Transforming Nanowires Into Nano-Tools Using Cation Exchange Reactions
A team of engineers from the University of Pennsylvania has transformed simple nanowires into reconfigurable materials and circuits, demonstrating a novel, self-assembling method for chemically creating nanoscale structures that are not possible to grow or obtain otherwise.
Berkeley Researchers Find New Route to Nano Self-Assembly
If the promise of nanotechnology is to be fulfilled, nanoparticles will have to be able to make something of themselves. An important advance towards this goal has been achieved by researchers with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) who have found a simple and yet powerfully robust way to induce nanoparticles to assemble themselves into complex arrays.
Caltech scientists solve decade-long mystery of nanopillar formations
Scientists at the California Institute of Technology (Caltech) have uncovered the physical mechanism by which arrays of nanoscale (billionths-of-a-meter) pillars can be grown on polymer films with very high precision, in potentially limitless patterns.
Harvard scientists bend nanowires into 2-D and 3-D structures
Taking nanomaterials to a new level of structural complexity, scientists have determined how to introduce kinks into arrow-straight nanowires, transforming them into zigzagging two- and three-dimensional structures with correspondingly advanced functions.
Smallest Nanoantennas for High-speed Data Networks
More than 120 years after the discovery of the electromagnetic character of radio waves by Heinrich Hertz, wireless data transmission dominates information technology.
Penn team uses self-assembly to make molecule-sized particles with patches of charge
Physicists, chemists and engineers at the University of Pennsylvania have demonstrated a novel method for the controlled formation of patchy particles, using charged, self-assembling molecules that may one day serve as drug-delivery vehicles to combat disease and perhaps be used in small batteries that store and release charge.
'NanoPen' may write new chapter in nanotechnology manufacturing
Researchers in California are reporting development of a so-called "NanoPen" that could provide a quick, convenient way of laying down patterns of nanoparticles - from wires to circuits - for making futuristic electronic devices, medical diagnostic tests, and other much-anticipated nanotech applications.
Caltech and IBM scientists use self-assembled DNA scaffolding to build tiny circuit boards
Scientists at the California Institute of Technology (Caltech) and IBM's Almaden Research Center have developed a new technique to orient and position self-assembled DNA shapes and patterns-or "DNA origami"-on surfaces that are compatible with today's semiconductor manufacturing equipment.
Capping a two-faced particle gives duke engineers complete control
Scientists drew fittingly from Roman mythology when they named a unique class of miniscule particles after the god Janus, who is usually depicted as having two faces looking in opposite directions.
More Nanostructures Current Events and Nanostructures News Articles
 |
Nanostructures and Nanomaterials: Synthesis, Properties & Applications by Guozhong Cao (Author) This important book focuses on the synthesis and fabrication of nanostructures and nanomaterials, but also includes properties and applications of nanostructures and nanomaterials, particularly inorganic nanomaterials. It provides balanced and comprehensive coverage of the fundamentals and processing techniques with regard to synthesis, characterization, properties, and applications of nanostructures and nanomaterials. Both chemical processing and lithographic techniques are presented in a systematic and coherent manner for the synthesis and fabrication of 0-D, 1-D, and 2-D nanostructures, as well as special nanomaterials such as carbon nanotubes and ordered mesoporous oxides. The book will serve as a general introduction to nanomaterials and nanotechnology for teaching and self-study... |
 |
Transport in Nanostructures by David K. Ferry (Author), Stephen M. Goodnick (Author), Jonathan Bird (Author) The advent of semiconductor structures whose characteristic dimensions are smaller than the mean free path of carriers has led to the development of novel devices, and advances in theoretical understanding of mesoscopic systems or nanostructures. This book has been thoroughly revised and provides a much-needed update on the very latest experimental research into mesoscopic devices and develops a detailed theoretical framework for understanding their behavior. Beginning with the key observable phenomena in nanostructures, the authors describe quantum confined systems, transmission in nanostructures, quantum dots, and single electron phenomena. Separate chapters are devoted to interference in diffusive transport, temperature decay of fluctuations, and non-equilibrium transport and... |
 |
Mesoscopic Electronics in Solid State Nanostructures by Thomas Heinzel (Author) This text treats electronic transport in the regime where conventional textbook models are no longer applicable, including the effect of electronic phase coherence, energy quantization and single-electron charging. This second edition is completely updated and expanded, and now comprises new chapters on spin electronics and quantum information processing, transport in inhomogeneous magnetic fields, organic/molecular electronics, and applications of field effect transistors. The book also provides an overview of semiconductor processing technologies and experimental techniques. With a number of examples and problems with solutions, this is an ideal introduction for students and beginning researchers in the field. "This book is a useful tool, too, for the experienced researcher to... |
 |
Theory of Transport Properties of Semiconductor Nanostructures (Electronic Materials Series) by Eckehard Scholl (Author) The theoretical understanding of transport properties of semiconductor structures on short length and short time scales, and in the nonlinear high-field regime is of particular relevance for future electronic and optoelectronic materials. In recent years great progress has been made in a variety of aspects. Theory of Transport Properties of Semiconductor Nanostructures presents a state-of-the-art overview of theoretical methods, results, and applications in the field. It contains eleven chapters which are written by leading researchers. This book starts with a tutorial introduction to the subject, then in the following five chapters a hierarchy of different approaches to transport theory is presented, descending from a macroscopic level (quasihydrodynamic simulation) via ... |
 |
Organic Nanostructures by Jerry L. Atwood (Editor), Jonathan W. Steed (Editor) Filling the need for a volume on the organic side of nanotechnology, this comprehensive overview covers all major nanostructured materials in one handy volume. Alongside metal organic frameworks, this monograph also treats other modern aspects, such as rotaxanes, catenanes, nanoporosity and catalysis. Detailed attention is paid to the chemistry, physics and materials science throughout, making this a definite must for all chemists. |
|
Semiconductor Nanostructures: Quantum states and electronic transport by Thomas Ihn (Author) This textbook describes the physics of semiconductor nanostructures with emphasis on their electronic transport properties. At its heart are five fundamental transport phenomena: quantized conductance, tunnelling transport, the Aharonov-Bohm effect, the quantum Hall effect, and the Coulomb blockade effect. The book starts out with the basics of solid state and semiconductor physics, such as crystal structure, band structure, and effective mass approximation, including spin-orbit interaction effects important for research in semiconductor spintronics. It contains material aspects such as band engineering, doping, gating, and a selection of nanostructure fabrication techniques. The book discusses the Drude-Boltzmann-Sommerfeld transport theory as well as conductance quantization and... | |
 |
Zinc Oxide Bulk, Thin Films and Nanostructures: Processing, Properties, and Applications by Chennupati Jagadish (Editor), Stephen J. Pearton (Editor) With an in-depth exploration of the following topics, this book covers the broad uses of zinc oxide within the fields of materials science and engineering: - Recent advances in bulk , thin film and nanowire growth of ZnO (including MBE, MOCVD and PLD), - The characterization of the resulting material (including the related ternary systems ZgMgO and ZnCdO), - Improvements in device processing modules (including ion implantation for doping and isolation ,Ohmic and Schottky contacts , wet and dry etching), - The role of impurities and defects on materials properties - Applications of ZnO in UV light emitters/detectors, gas, biological and chemical-sensing, transparent electronics, spintronics and thin film |
 |
Electrochemistry at the Nanoscale (Nanostructure Science and Technology) by Patrik Schmuki (Editor), Sannakaisa Virtanen (Editor) For centuries, electrochemistry has played a key role in technologically important areas such as electroplating or corrosion. In recent decades, electrochemical methods are receiving increasing attention in important strongly growing fields of science and technology such as nanosciences (nanoelectrochemistry) and life-sciences (organic and biological electrochemistry). Characterization, modification and understanding of various electrochemical interfaces or electrochemical processes at the nanoscale, has led to a huge increase of the scientific interest in electrochemical mechanisms as well as of application of electrochemical methods in novel technologies. This book presents exciting emerging scientific and technological aspects of the introduction of the nanodimension in... |
 |
Quantum Networks: Dynamics of Open Nanostructures by Günter Mahler (Author), Volker A. Weberruß (Author) Quantum Networks is focused on density matrix theory cast into a product operator representation, particularly adapted to describing networks of finite state subsystems. This approach is important for understanding non-classical aspects such as single subsystem and multi-subsystem entanglement. An intuitive picture evolves of how these features are generated and destroyed by interactions with the environment. This second edition has been revised and enlarged. For better clarity the text has been partly reorganized and figures and formulae are presented in a more attractive way. |
 |
Ultrafast Spectroscopy of Semiconductors and Semiconductor Nanostructures (Springer Series in Solid-State Sciences) by Jagdeep Shah (Author) This subject is currently one of the most exciting areas of research in condensed-matter physics. Direct investigation of fundamental dynamical processes in semiconductors, exploiting the remarkable recent development of pulses with pulse widths less than 5fs, has led to new insights into fundamental physics and ultra-high-speed electronic and opto-electronic devices. This new edition presents the recent developments: femtosecond dynamics demonstrating quantum kinetics and higher-order correlations, measurement of the amplitude and phase of ultrafast nonlinear and linear signals, femtosecond coherent emission dynamics, and ultrafast dynamics of microcavities and lower-dimensional structures such as quantum wires and dots. |
| © 2009 BrightSurf.com |