Download or read book Metallic Multilayers at the Nanoscale written by and published by . This book was released on 1994 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of multilayer structures has been driven by a wide range of commercial applications requiring enhanced material behaviors. Innovations in physical vapor deposition technologies, in particular magnetron sputtering, have enabled the synthesis of metallic-based structures with nanoscaled layer dimensions as small as one-to-two monolayers. Parameters used in the deposition process are paramount to the Formation of these small layer dimensions and the stability of the structure. Therefore, optimization of the desired material properties must be related to assessment of the actual microstructure. Characterization techniques as x-ray diffraction and high resolution microscopy are useful to reveal the interface and layer structure-whether ordered or disordered crystalline, amorphous, compositionally abrupt or graded, and/or lattice strained Techniques for the synthesis of metallic multilayers with subnanometric layers will be reviewed with applications based on enhancing material behaviors as reflectivity and magnetic anisotropy but with emphasis on experimental studies of mechanical properties.

Download or read book Mechanics of Nanoscale Metallic Multilayers written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Layered composites of Cu/Nb with incoherent interfaces achieve very high strength levels. Interfaces play a crucial role in materials strength by acting as barriers to slip. Atomistic models of Cu/Nb bilayers are used to explore the origins of this resistance. The models clearly show that dislocations near an interface experience an attraction toward the interface. This attraction is caused by shear of the interface induced by the stress field of the dislocation. More importantly, atomistic simulations also reveal that interfacial dislocations easily move in interfaces by both glide and climb. Integrating these findings into a micro-scale model, we develop a three-dimensional crystal elastic-plastic model to describe the mechanical behavior of nanoscale metallic multi layers.

Download or read book Metallic Multilayers written by A. Chamberod and published by Trans Tech Publications Ltd. This book was released on 1991-01-01 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains a series of lectures given in a Summer School held in Aussois (France) in September 1989. It offers a global perspective on the current state-of-the-art in the rapidly emerging field of metallic multilayered structures.

Download or read book Identifying Deformation and Strain Hardening Behaviors of Nanoscale Metallic Multilayers Through Nano wear Testing written by and published by . This book was released on 2016 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: In complex loading conditions (e.g. sliding contact), mechanical properties, such as strain hardening and initial hardness, will dictate the long-term performance of materials systems. With this in mind, the strain hardening behaviors of Cu/Nb nanoscale metallic multilayer systems were examined by performing nanoindentation tests within nanoscratch wear boxes and undeformed, as-deposited regions. Both the architecture and substrate influence were examined by utilizing three different individual layer thicknesses (2, 20, and 100 nm) and two total film thicknesses (1 and 10 [mu]m). After nano-wear deformation, multilayer systems with thinner layers showed less volume loss as measured by laser scanning microscopy. Additionally, the hardness of the deformed regions significantly rose with respect to the as-deposited measurements, which further increased with greater wear loads. Strain hardening exponents for multilayers with thinner layers (2 and 20 nm, n ≈ 0.018 and n ≈ 0.022 respectively) were less than was determined for 100 nm systems (n ≈ 0.041). These results suggest that singledislocation based deformation mechanisms observed for the thinner systems limit the extent of achievable strain hardening. This conclusion indicates that impacts of both architecture strengthening and strain hardening must be considered to accurately predict multilayer performance during sliding contact across varying length scales.

Download or read book Atomistic Studies of Deformation Mechanisms in Nanoscale Multilayered Metallic Composites written by Shuai Shao and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this thesis is to understand the interaction between dislocations and various metallic interfaces in nanoscale metallic multilayers (NMM). At lower strain rates, this mean understanding the effect of interfaces to the strain hardening of the NMMs; at higher strain rates, this means the effect of the interfaces on the spallation strengths of the NMMs. NMMs possess ultra-high strength level which is owing to the interactions between single dislocations (i.e. no pile-up) and interfaces. In this thesis, aiming at the goal, using atomistic simulations several nanoscale metallic multilayers subjected to different loading conditions and strain rates are being considered.

Download or read book Residual Stress Within Nanoscale Metallic Multilayer Systems During Thermal Cycling written by and published by . This book was released on 2015 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Projected applications for nanoscale metallic multilayers will include wide temperature ranges. Since film residual stress has been known to alter system reliability, stress development within new film structures with high interfacial densities should be characterized to identify potential long-term performance barriers. To understand factors contributing to thermal stress evolution within nanoscale metallic multilayers, stress in Cu/Nb systems adhered to Si substrates was calculated from curvature measurements collected during cycling between 25 °C and 400 °C. Additionally, stress within each type of component layers was calculated from shifts in the primary peak position from in-situ heated X-ray diffraction. The effects of both film architecture (layer thickness) and layer order in metallic multilayers were tracked and compared with monolithic Cu and Nb films. Analysis indicated that the thermoelastic slope of nanoscale metallic multilayer films depends on thermal expansion mismatch, elastic modulus of the components, and also interfacial density. The layer thickness (i.e. interfacial density) affected thermoelastic slope magnitude while layer order had minimal impact on stress responses after the initial thermal cycle. When comparing stress responses of monolithic Cu and Nb films to those of the Cu/Nb systems, the nanoscale metallic multilayers show a similar increase in stress above 200 °C to the Nb monolithic films, indicating that Nb components play a larger role in stress development than Cu. Local stress calculations from X-ray diffraction peak shifts collected during heating reveal that the component layers within a multilayer film respond similarly to their monolithic counterparts.

Download or read book Microstructure and Properties of Micro and Nanoscale Materials Films and Coatings NAP 2019 written by Alexander D. Pogrebnjak and published by Springer Nature. This book was released on 2020-01-28 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the findings of experimental and theoretical (including first-principles molecular dynamics simulation) studies of nanostructured and nanocomposite metal-based materials, and nanoscale multilayer coatings fabricated by physical or chemical vapor deposition, magnetron sputtering, electrospark alloying, ionic layer absorption, contact melting, and high-current electron beam irradiation. It also discusses novel methods of nanocomposite formation, as well as the structure of the deposited films, coatings and other nanoscale materials, their elemental and phase composition, and their physical–mechanical, tribological, magnetic and electrical properties. Lastly, it explores the influence of a various surface modification methods, such as thermal annealing, pulsed laser modification, and thermomechanical and ultrasonic treatment, as well as different properties of nanostructured films.

Download or read book Surfaces and Interfaces of Metal Oxide Thin Films Multilayers Nanoparticles and Nano composites written by Alejandro G. Roca and published by Springer Nature. This book was released on 2021-09-20 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a general overview and current state of the art of different types of metal oxide nanomaterials, either in nanoparticles or thin film structure. It covers from the development and optimization of different nanofabrication/synthesis techniques for nanostructures which are currently the attention of the research community, the study of the structure and interactions by different characterization techniques of heterostructured materials and the final impact in different applications such as nanotherapy, data storage, super magnets, high-frequency devices. The book’s 13 chapters provide deep insight into the intriguing science of oxide materials and include contributions on novel technologies to fabricate nanomaterials with a broad range of functional properties (semiconducting, magnetic, ferroelectric, thermoelectric, optical, flexible and mechanical). This book is intended to the experts for consolidation of their knowledge but also for students who aim to learn and get basics of nanostructured metal oxides in diverse forms.

Download or read book Handbook of Nanomaterials Properties written by Bharat Bhushan and published by Springer Science & Business Media. This book was released on 2014-03-13 with total page 1467 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanomaterials attract tremendous attention in recent researches. Although extensive research has been done in this field it still lacks a comprehensive reference work that presents data on properties of different Nanomaterials. This Handbook of Nanomaterials Properties will be the first single reference work that brings together the various properties with wide breadth and scope.

Download or read book Growth and Nano structural Studies of Metallic Multilayers for X ray Mirrors written by Naureen Ghafoor and published by . This book was released on 2005 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nanoscale Strengthening Mechanisms in Metallic Thin Film Systems written by Rachel Lynn Schoeppner and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Nano-scale strengthening mechanisms for thin films were investigated for systems governed by two different strengthening techniques: nano-laminate strengthening and oxide dispersion strengthening. Films were tested under elevated temperature conditions to investigate changes in deformation mechanisms at different operating temperatures, and the structural stability. Both systems exhibit remarkable stability after annealing and thus long-term reliability.

Download or read book The Effects of Length Scale on the Deformation Behavior of Metallic Multilayers Part II written by and published by . This book was released on 2002 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: The experimental observations described in a companion presentation of the same title by Misra et al. highlight that unique, non-bulk rolling textures are achieved in nanoscale multilayered thin films. Specifically, Cu/Nb multilayers deposited with an initial Kudjumov-Sachs orientation relation between Cu and Nb grains and with an initial individual layer thickness of 75nm preserve that relation during rolling. In contrast, samples with micron-scale individual layer thickness do not. To help understand this layer-dependent response, a crystal plasticity model is presented in which the Cu and Nb phases respond by slip on {l_brace}111{r_brace}/110 systems in the fcc Cu case, and {l_brace}110{r_brace} / 111 systems in the bcc Nb phase. Grains within each layered phase are required to plastically deform by a reduction in thickness and corresponding elongation in the rolling direction, with zero plastic strain along the transverse axis. The model also adopts the observation for nano-scale multilayers that the Kudjumov-Sachs orientation relation is preserved; in particular, the e 1 11> Cu and e1 10> Nb directions remain parallel to the interface normal during rolling. The crystal plasticity model then furnishes the minimum plastic work to deform a grain, as a function of grain orientation. For Cu grains, the plastic work is invariant of grain orientation, provided the critical resolved shear stress is uniform on all fcc slip systems. However, the corresponding plastic work in Nb grains is very dependent on grain orientation and has a strong minimum. This large anisotropy serves as a driving force for Nb grains to rotate around their 110 interface normal, toward the minimum. The resulting prediction for rolling texture in Nb layers agrees well with experimental observations in nanoscale Cu/Nb multilayers.

Download or read book Nanoscale Devices Fundamentals and Applications written by Rudolf Gross and published by Springer Science & Business Media. This book was released on 2007-05-16 with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book collects papers on the fundamentals and applications of nanoscale devices, first presented at the NATO Advanced Research Workshop on Nanoscale Devices – Fundamentals and Applications held in Kishinev, Moldova, in September 2004. The focus is on the synthesis and characterization of nanoscale magnetic materials; fundamental physics and materials aspects of solid-state nanostructures; development of novel device concepts and design principles for nanoscale devices; and on applications in electronics with emphasis on defence against the threat of terrorism.

Download or read book Investigating Deformation and Failure Mechanisms in Nanoscale Multilayer Metallic Composites written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the history of materials science there are many examples of materials discoveries that have made superlative materials; the strongest, lightest, or toughest material is almost always a goal when we invent new materials. However, often these have been a result of enormous trial and error approaches. A new methodology, one in which researchers design, from the atoms up, new ultra-strong materials for use in energy applications, is taking hold within the science and engineering community. This project focused on one particular new classification of materials; nanolaminate metallic composites. These materials, where two metallic materials are intimately bonded and layered over and over to form sheets or coatings, have been shown over the past decade to reach strengths over 10 times that of their constituents. However, they are not yet widely used in part because while extremely strong (they don't permanently bend), they are also not particularly tough (they break relatively easily when notched). Our program took a coupled approach to investigating new materials systems within the laminate field. We used computational materials science to explore ways to institute new deformation mechanisms that occurred when a tri-layer, rather than the more common bi-layer system was created. Our predictions suggested that copper-nickel or copper-niobium composites (two very common bi-layer systems) with layer thicknesses on the order of 20 nm and then layered 100's of times, would be less tough than a copper-nickel-niobium metallic composite of similar thicknesses. In particular, a particular mode of permanent deformation, cross-slip, could be activated only in the tri-layer system; the crystal structure of the other bi-layers would prohibit this particular mode of deformation. We then experimentally validated this predication using a wide range of tools. We utilized a DOE user facility, the Center for Integrated Nanotechnology (CINT), to fabricate, for the first time, these tri-layer composites. CINT formed nanolaminate composites were tested in tension, with bulge testing, using nanoindentation, and using micro-compression testing to demonstrate that the tri-layer films were indeed tougher and hardened more during deformation (they got stronger as we deformed them) than equivalent bi-layers. The seven graduate students, 4 post-docs and research faculty, and the two faculty co-PI's were able to create a collaborated computational prediction and experimental validation team to demonstrate the benefits of this class of materials to the community. The computational work crossed from atomistic to bulk simulations, and the experiments coupled form nm-scale to the mm scale; closely matching the simulations. The simulations provided viable mechanisms that explained the observed results, and new experimental results were used to push the boundaries of the simulation tools. Over the life of the 7 years of this program we proved that tri-layer nanolaminate metallic composite systems exceeded the mechanical performance of bi-layer systems if the right materials were chosen, and that the mechanism responsible for this was tied to the cross slip of dislocations. With 30 journal publications resulting from this work we have broadly disseminated this family of results to the scientific community.

Download or read book Metallic Nanoparticles written by and published by Elsevier. This book was released on 2008-11-21 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metallic nanoparticles display fascinating properties that are quite different from those of individual atoms, surfaces or bulk rmaterials. They are a focus of interest for fundamental science and, because of their huge potential in nanotechnology, they are the subject of intense research effort in a range of disciplines. Applications, or potential applications, are diverse and interdisciplinary. They include, for example, use in biochemistry, in catalysis and as chemical and biological sensors, as systems for nanoelectronics and nanostructured magnetism (e.g. data storage devices), where the drive for further miniaturization provides tremendous technological challenges and, in medicine, there is interest in their potential as agents for drug delivery.The book describes the structure of metallic nanoparticles, the experimental and theoretical techniques by which this is determined, and the models employed to facilitate understanding. The various methods for the production of nanoparticles are outlined. It surveys the properties of clusters and the methods of characterisation, such as photoionization, optical spectroscopy, chemical reactivity and magnetic behaviour, and discusses element-specific information that can be extracted by synchrotron-based techniques such as EXAFS, XMCD and XMLD. The properties of clusters can vary depending on whether they are free, deposited on a surface or embedded in a matrix of another material; these issues are explored. Clusters on a surface can be formed by the diffusion and aggregation of atoms; ways of modelling these processes are described. Finally we look at nanotechnology and examine the science behind the potential of metallic nanoparticles in chemical synthesis, catalysis, the magnetic separation of biomolecules, the detection of DNA, the controlled release of molecules and their relevance to data storage.The book addresses a wide audience. There was a huge development of the subject beginning in the mid-1980s where researchers began to study the properties of free nanoparticle and models were developed to describe the observations. The newcomer is introduced to the established models and techniques of the field without the need to refer to other sources to make the material accessible. It then takes the reader through to the latest research and provides a comprehensive list of references for those who wish to pursue particular aspects in more detail. It will also be an invaluable handbook for the expert in a particular aspect of nanoscale research who wishes to acquire knowledge of other areas.The authors are specialists in different aspects of the subject with expertise in physics and chemistry, experimental techniques and computational modelling, and in interdisciplinary research. They have collaborated in research. They have also collaborated in writing this book, with the aim from the outset of making it is a coherent whole rather than a series of independent loosely connected articles. * Appeals to a wide audience* Provides an introduction to established models and techniques in the field* Comprehensive list of references

Download or read book Surfaces and Interfaces of Metal Oxide Thin Films Multilayers Nanoparticles and Nano composites written by Alejandro G. Roca and published by Springer. This book was released on 2022-09-22 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a general overview and current state of the art of different types of metal oxide nanomaterials, either in nanoparticles or thin film structure. It covers from the development and optimization of different nanofabrication/synthesis techniques for nanostructures which are currently the attention of the research community, the study of the structure and interactions by different characterization techniques of heterostructured materials and the final impact in different applications such as nanotherapy, data storage, super magnets, high-frequency devices. The book’s 13 chapters provide deep insight into the intriguing science of oxide materials and include contributions on novel technologies to fabricate nanomaterials with a broad range of functional properties (semiconducting, magnetic, ferroelectric, thermoelectric, optical, flexible and mechanical). This book is intended to the experts for consolidation of their knowledge but also for students who aim to learn and get basics of nanostructured metal oxides in diverse forms.

Download or read book Transport Phenomena in Micro and Nanoscale Functional Materials and Devices written by Joao B. Sousa and published by William Andrew. This book was released on 2021-03-23 with total page 485 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transport Phenomena in Micro- and Nanoscale Functional Materials and Devices offers a pragmatic view on transport phenomena for micro- and nanoscale materials and devices, both as a research tool and as a means to implant new functions in materials. Chapters emphasize transport properties (TP) as a research tool at the micro/nano level and give an experimental view on underlying techniques. The relevance of TP is highlighted through the interplay between a micro/nanocarrier’s characteristics and media characteristics: long/short-range order and disorder excitations, couplings, and in energy conversions. Later sections contain case studies on the role of transport properties in functional nanomaterials. This includes transport in thin films and nanostructures, from nanogranular films, to graphene and 2D semiconductors and spintronics, and from read heads, MRAMs and sensors, to nano-oscillators and energy conversion, from figures of merit, micro-coolers and micro-heaters, to spincaloritronics. Presents a pragmatic description of electrical transport phenomena in micro- and nanoscale materials and devices from an experimental viewpoint Provides an in-depth overview of the experimental techniques available to measure transport phenomena in micro- and nanoscale materials Features case studies to illustrate how each technique works Highlights emerging areas of interest in micro- and nanomaterial transport phenomena, including spintronics