Download or read book First Principles Studies of Surface Energies of Magnetic Full Heuslers and Machine Learning of Hybrid Perovskites written by Joseph Wong and published by . This book was released on 2019 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials design is a cornerstone of every device. Historically, the materials selection process was characterized by a time consuming, expensive, Edisonian approach. In recent years however, rapid advancements in computational power and materials simulation software has spawned the field of computational materials science. Computational materials science opens a new avenue to materials discovery called high-throughput materials design. This approach allows for rapid prototyping of materials in a large, complex chemical space. In this work, the scope of highthroughput materials design approach is used in the analysis of several topics: magnetic full-heuslers, hybrid perovskites, and grain boundary structures. Using high-throughput density functional theory (DFT), we study the surface energy of 68 magnetic full heuslers to guide the synthesis of magnetic tunnel junctions for applications in memory storage devices. We employ a high-throughput machine learning approach to explore the chemical space of single and double perovskite materials for applications in stable, high-performance solar cells. We also look deeper into hybrid perovskite materials in a literature review of two-dimensional hybrid perovskites, which demonstrate greater stability and tunable band gaps with simple fabrication routes. In addition, their strong binding energies lead to strong light emitting properties, with potential applications in light emitting diode devices. We also examine the configurational entropy of yttria-stabilized zirconia grain boundaries and provide example usage and applications of AIMSGB, an open-source python library for grain boundary structure generation.

Download or read book First Principles Studies of ABO3 Perovskite Surfaces and Nanostructures written by Ghanshyam Pilania and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book First Principles Studies of New Type Magnetic Semiconductor in Double Perovskites Structure and 2 dimension Honeycomb Structure Compounds written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hybrid Perovskite Solar Cells written by Hiroyuki Fujiwara and published by John Wiley & Sons. This book was released on 2022-01-10 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unparalleled coverage of the most vibrant research field in photovoltaics! Hybrid perovskites, revolutionary game-changing semiconductor materials, have every favorable optoelectronic characteristic necessary for realizing high efficiency solar cells. The remarkable features of hybrid perovskite photovoltaics, such as superior material properties, easy material fabrication by solution-based processing, large-area device fabrication by an inkjet technology, and simple solar cell structures, have brought enormous attentions, leading to a rapid development of the solar cell technology at a pace never before seen in solar cell history. Hybrid Perovskite Solar Cells: Characteristics and Operation covers extensive topics of hybrid perovskite solar cells, providing easy-to-read descriptions for the fundamental characteristics of unique hybrid perovskite materials (Part I) as well as the principles and applications of hybrid perovskite solar cells (Part II). Both basic and advanced concepts of hybrid perovskite devices are treated thoroughly in this book; in particular, explanatory descriptions for general physical and chemical aspects of hybrid perovskite photovoltaics are included to provide fundamental understanding. This comprehensive book is highly suitable for graduate school students and researchers who are not familiar with hybrid perovskite materials and devices, allowing the accumulation of the accurate knowledge from the basic to the advanced levels.

Download or read book Magnetic Perovskites written by Asish K Kundu and published by Springer. This book was released on 2016-02-11 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetic perovskite with multi functional properties (magneto-resistive, magneto-dielectric, multiferroics, spintronics, etc.) have attracted increasing attention due to their possible applications towards storage materials and intriguing fundamental Physics. Despite the numerous investigations on multi functional materials in the past few years, a very few magnetic perovskites have been known to realize as ferromagnetic-insulators. In perovskites centred transition metal oxides strong interplay between lattice, charge, spin and/or orbital degrees of freedom provide a fantastic playground to tune their physical properties. The main purpose of this book is to introduce the phenomenon and physics of complex magnetism (phase separation, spin glass, frustrations, etc.) in perovskite manganites and cobaltites via an experimental approach. The book is organized into four chapters; Chap. 1 gives a brief introduction of various interesting phenomena in magnetic perovskites. Chapter 2 describes the results of the investigations on electronic phase separation and glassy ferromagnetism of the hole-doped perovskite manganites and cobaltites. Ordered and disordered effects and related aspects in hole-doped perovskite cobaltites are described in Chap. 3. Finally, in Chap. 4 the bismuth based magnetic perovskite is discussed.

Download or read book First principles Studies of Perovskite Thin Films and Heterostructures written by Kurt David Fredrickson and published by . This book was released on 2015 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: The growth of oxides on semiconductors is of great interest for electronics applications; however, the effects of film growth, atomic adsorption, and strain can have fundamental effects on the properties of the oxides in question. In this dissertation, we use density functional theory to calculate the properties of SrTiO3 and BaTiO3, and discover the effects of the environment on the electronic and atomic properties of these systems. We examine the effects of H adsorption on the SrTiO3 and BaTiO3(001) surfaces, and discover the coverage-dependent onset and retreat of metallic surface states. We calculate the effect of Pt film growth on BaTiO3, and study the effects on the polarization of BaTiO3 for different Pt/BaTiO3 interfaces. We study how strain and interfacial chemistry affect the ferroelectricity of BaTiO3/Ge and BaTiO3/SrTiO3/Ge heterostructures. We also discuss the development of two-dimensional conducting states created in BaTiO3/SrTiO3 heterostructures.

Download or read book First Principles Study of Electronic and Magnetic Structures in Double Perovskites written by Molly Ball and published by . This book was released on 2017 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: At present, electronic devices are reaching their storage and processing limit causing a major push to find materials that can be used in the next generation of devices. Double perovskites with A2BB'O6 stoichiometry form one of the leading classes of materials currently being studied as a potential candidate because of their extremely wide range and tunability of functional properties, along with economic and highly scalable synthesis routes. Having a thorough understanding of their electronic and magnetic structure and their dependence on composition and local structure is the basis for targeted development of novel and optimized double perovskites. While the body of knowledge and rules within the field of materials chemistry has enabled many previous discoveries, recent developments within density functional theory (DFT) allow by now a rather realistic description of the electronic and magnetic properties of materials and especially identification of their origin from geometry and orbital structure. This thesis details computational work based on DFT within several collaborative studies to better understand the electronic and magnetic properties of double perovskites and related materials that show promise for future use in multifunctional devices. First, we will begin with a general introduction to the double perovskite structure, their properties, and the computational methods used to study them. In the next section, we will look at the case of the antiferromagnetic, insulating double perovskite Sr2CoOsO6, where measurements showed that the transition metal ions in the two sublattices undergo magnetic ordering independently of each other, indicating weak magnetic short-range coupling and a dominance of longer-range interactions, which has previously not been observed. Here, we performed DFT calculations to extract the exchange strengths between the ions and explain this unique dominance of the long-range interactions. Then, we will look at studies done on thin films of Sr2CrReO6, where our experimental collaborators found extraordinarily large anisotropy fields and record-breaking strain-tunable magnetocrystalline anisotropy (MCA). We employed first principles calculations that examine the dependence of MCA on strain and could identify orbital magnetism on the Re atoms as the origin of this unique phenomenon. In the last section, we introduce double perovskites as novel lead-free halide solar cell materials, with current focus on Cs2AgBiBr6 and Cs2AgBiCl6. While organic Pb based halides that can be synthesized without expensive clean rooms have achieved within record time efficiencies that rival that of traditional semiconductor based materials, creating quite a buzz within the field of photovoltaics, their Pb content and lacking air stability represented severe roadblocks towards market introduction. Here, we show with band structure calculations that spin-orbit coupling is a much more dominant interaction than in traditional semiconductors and thus needs to be considered when designing novel materials for maximum efficiency. The results of this study have given momentum to investigate additional halides double perovskites. Finally, we will summarize and discuss the importance of computational modeling in order to explore the wide and to date little explored composition space of double perovskites, one of the currently most promising materials classes for novel devices with unique and extremely tunable properties.

Download or read book First principles Study of Electromechanical and Polar Properties in Perovskite Oxides and Half Heusler Semiconductors written by Anindya Roy and published by . This book was released on 2011 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis discusses electromechanical and polar properties in two well-known classes of materials, perovskite oxides and half-Heusler compounds, using first-principles calculations. Certain features of the ab initio codes, such as the capability to calculate polarization based on the modern theory of polarization, or to apply a finite electric field, are central to the problems presented in this thesis. Hence these formalisms are discussed, following a brief opening section on the basic methodology of density-functional theory. The first problem presented in this thesis concerns the nonlinear piezoelectric response of ferroelectric PbTiO3 for the case of a polarization-enhancing electric field applied along the tetragonal axis. The dependence of the c/a ratio on electric field is found to be almost linear in the range up to 500 MV/m, contrary to what expected from Landau-Devonshire theory, but in qualitative agreement with a recent experiment. In the second problem we study the energy landscape and ferroelectric states of double perovskites of the form AA'BB'O6 in which the atoms on both the A and B sites are arranged in rock-salt order. If a ferroelectric instability occurs, the energy landscape will tend to have minima with the polarization along tetrahedral directions, leading to a rhombohedral phase, or along Cartesian directions, leading to an orthorhombic phase. We are not aware of compounds naturally occurring in this structure, although they might be synthesized experimentally. In the final problem, we use a first-principles rational-design approach to search a large materials family, half-Heusler compounds to identify semiconductors, and then compute their piezoelectric properties. This previously-unrecognized class of piezoelectrics may benefit greatly from calculations such as those presented here. Our work may provide guidance for experimental verification of existing compounds and for the experimental realization of other potential candidates.

Download or read book Energy Band Gap Tuning of Halide Perovskite Materials from First Principles written by Manaswita Kar and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Solar cells based on hybrid perovskites materials have become significantly important among the third generation photovoltaics over the last few years. The first solid state solar cell was reported in 2012. Over the years, the power conversion efficiencies of these devices have increased at a tremendous pace and this has made the perovskite solar cell devices a serious competitor in the well-established market of thin-film and wafer technologies. Over time, a large number of articles on this topic has been published in peer-reviewed journals. The presence of lead in the most efficient hybrid perovskite materials have raised questions about the possible toxicity of these devices and the extent of their environmental impact. Therefore, a lot of research has been devoted to finding alternative perovskite materials with similar or even better opto-electronic properties. An alternative strategy to improve the efficiency of thin film solar cells is to build efficient tandem cells by combining two or more perovskite materials with specifically tailored band gaps. [...].

Download or read book Hands On Mathematics for Deep Learning written by Jay Dawani and published by Packt Publishing Ltd. This book was released on 2020-06-12 with total page 347 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive guide to getting well-versed with the mathematical techniques for building modern deep learning architectures Key FeaturesUnderstand linear algebra, calculus, gradient algorithms, and other concepts essential for training deep neural networksLearn the mathematical concepts needed to understand how deep learning models functionUse deep learning for solving problems related to vision, image, text, and sequence applicationsBook Description Most programmers and data scientists struggle with mathematics, having either overlooked or forgotten core mathematical concepts. This book uses Python libraries to help you understand the math required to build deep learning (DL) models. You'll begin by learning about core mathematical and modern computational techniques used to design and implement DL algorithms. This book will cover essential topics, such as linear algebra, eigenvalues and eigenvectors, the singular value decomposition concept, and gradient algorithms, to help you understand how to train deep neural networks. Later chapters focus on important neural networks, such as the linear neural network and multilayer perceptrons, with a primary focus on helping you learn how each model works. As you advance, you will delve into the math used for regularization, multi-layered DL, forward propagation, optimization, and backpropagation techniques to understand what it takes to build full-fledged DL models. Finally, you’ll explore CNN, recurrent neural network (RNN), and GAN models and their application. By the end of this book, you'll have built a strong foundation in neural networks and DL mathematical concepts, which will help you to confidently research and build custom models in DL. What you will learnUnderstand the key mathematical concepts for building neural network modelsDiscover core multivariable calculus conceptsImprove the performance of deep learning models using optimization techniquesCover optimization algorithms, from basic stochastic gradient descent (SGD) to the advanced Adam optimizerUnderstand computational graphs and their importance in DLExplore the backpropagation algorithm to reduce output errorCover DL algorithms such as convolutional neural networks (CNNs), sequence models, and generative adversarial networks (GANs)Who this book is for This book is for data scientists, machine learning developers, aspiring deep learning developers, or anyone who wants to understand the foundation of deep learning by learning the math behind it. Working knowledge of the Python programming language and machine learning basics is required.

Download or read book Applications of Machine Learning written by Prashant Johri and published by Springer Nature. This book was released on 2020-05-04 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers applications of machine learning in artificial intelligence. The specific topics covered include human language, heterogeneous and streaming data, unmanned systems, neural information processing, marketing and the social sciences, bioinformatics and robotics, etc. It also provides a broad range of techniques that can be successfully applied and adopted in different areas. Accordingly, the book offers an interesting and insightful read for scholars in the areas of computer vision, speech recognition, healthcare, business, marketing, and bioinformatics.

Download or read book Artificial Intelligence for Materials Science written by Yuan Cheng and published by Springer Nature. This book was released on 2021-03-26 with total page 231 pages. Available in PDF, EPUB and Kindle. Book excerpt: Machine learning methods have lowered the cost of exploring new structures of unknown compounds, and can be used to predict reasonable expectations and subsequently validated by experimental results. As new insights and several elaborative tools have been developed for materials science and engineering in recent years, it is an appropriate time to present a book covering recent progress in this field. Searchable and interactive databases can promote research on emerging materials. Recently, databases containing a large number of high-quality materials properties for new advanced materials discovery have been developed. These approaches are set to make a significant impact on human life and, with numerous commercial developments emerging, will become a major academic topic in the coming years. This authoritative and comprehensive book will be of interest to both existing researchers in this field as well as others in the materials science community who wish to take advantage of these powerful techniques. The book offers a global spread of authors, from USA, Canada, UK, Japan, France, Russia, China and Singapore, who are all world recognized experts in their separate areas. With content relevant to both academic and commercial points of view, and offering an accessible overview of recent progress and potential future directions, the book will interest graduate students, postgraduate researchers, and consultants and industrial engineers.

Download or read book NASA Glenn Coefficients for Calculating Thermodynamic Properties of Individual Species written by Bonnie J. McBride and published by . This book was released on 2002 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microwave Absorbing Materials written by Yuping Duan and published by CRC Press. This book was released on 2016-10-14 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the phenomenal development of electromagnetic wave communication devices and stealth technology, electromagnetic wave absorbing materials have been attracting attention as antielectromagnetic interference slabs, stealth materials, self-concealing technology, and microwave darkrooms. This book starts with the fundamental theory of electromagnetic wave absorption in loss medium space, followed by a discussion of different microwave absorbents, such as manganese dioxide, iron-based composite powder, conductive polyaniline, barium titanate powder, and manganese nitride. Then, structural absorbing materials are explored, including multilayer materials, new discrete absorbers, microwave absorption coatings, cement-based materials, and structural pyramid materials. Many of the graphics demonstrate not only the principles of physics and experimental results but also the methodology of computing. The book will be useful for graduate students of materials science and engineering, physics, chemistry, and electrical and electronic engineering; researchers in the fields of electromagnetic functional materials and nanoscience; and engineers in the fields of electromagnetic compatibility and stealth design.

Download or read book Materials for Sustainable Energy written by Vincent Dusastre and published by World Scientific. This book was released on 2011 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: The search for cleaner, cheaper, smaller and more efficient energy technologies has to a large extent been motivated by the development of new materials. The aim of this collection of articles is therefore to focus on what materials-based solutions can offer and show how the rationale design and improvement of their physical and chemical properties can lead to energy-production alternatives that have the potential to compete with existing technologies. In terms of alternative means to generate electricity that utilize renewable energy sources, the most dramatic breakthroughs for both mobile (i.e., transportation) and stationary applications are taking place in the fields of solar and fuel cells. And from an energy-storage perspective, exciting developments can be seen emerging from the fields of rechargeable batteries and hydrogen storage.

Download or read book Spin Dynamics in Two Dimensional Quantum Materials written by Marc Vila Tusell and published by Springer Nature. This book was released on 2021-11-10 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis focuses on the exploration of nontrivial spin dynamics in graphene-based devices and topological materials, using realistic theoretical models and state-of-the-art quantum transport methodologies. The main outcomes of this work are: (i) the analysis of the crossover from diffusive to ballistic spin transport regimes in ultraclean graphene nonlocal devices, and (ii) investigation of spin transport and spin dynamics phenomena (such as the (quantum) spin Hall effect) in novel topological materials, such as monolayer Weyl semimetals WeTe2 and MoTe2. Indeed, the ballistic spin transport results are key for further interpretation of ultraclean spintronic devices, and will enable extracting precise values of spin diffusion lengths in diffusive transport and guide experiments in the (quasi)ballistic regime. Furthermore, the thesis provides an in-depth theoretical interpretation of puzzling huge measured efficiencies of the spin Hall effect in MoTe2, as well as a prediction of a novel canted quantum spin Hall effect in WTe2 with spins pointing in the yz plane.

Download or read book Metallic Films for Electronic Optical and Magnetic Applications written by Katayun Barmak and published by Woodhead Publishing. This book was released on 2014-02-13 with total page 671 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metallic films play an important role in modern technologies such as integrated circuits, information storage, displays, sensors, and coatings. Metallic Films for Electronic, Optical and Magnetic Applications reviews the structure, processing and properties of metallic films. Part one explores the structure of metallic films using characterization methods such as x-ray diffraction and transmission electron microscopy. This part also encompasses the processing of metallic films, including structure formation during deposition and post-deposition reactions and phase transformations. Chapters in part two focus on the properties of metallic films, including mechanical, electrical, magnetic, optical, and thermal properties. Metallic Films for Electronic, Optical and Magnetic Applications is a technical resource for electronics components manufacturers, scientists, and engineers working in the semiconductor industry, product developers of sensors, displays, and other optoelectronic devices, and academics working in the field. Explores the structure of metallic films using characterization methods such as x-ray diffraction and transmission electron microscopy Discusses processing of metallic films, including structure formation during deposition and post-deposition reactions and phase transformations Focuses on the properties of metallic films, including mechanical, electrical, magnetic, optical, and thermal properties