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Book Growth of Perovskite Oxides on Low cost Substrates by Pulsed Laser Deposition and the Characterization of Their Macroscopic and Microscopic Properties

Download or read book Growth of Perovskite Oxides on Low cost Substrates by Pulsed Laser Deposition and the Characterization of Their Macroscopic and Microscopic Properties written by Marie El Rami and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Different perovskite oxides were grown by pulsed laser deposition on “low-cost” substrates through two different approaches. The first approach involves the use of [Ca2Nb3O10]- nanosheets (NS) as seed layer for the integration of vanadates on amorphous glass substrates. Notably, a global out-of-plane texture of the films, promoted by NS was revealed. The impact of the films thickness on their macroscopic electric-transport properties was investigated using DC transport and spectroscopic ellipsometry measurements. Furthermore, atomic force microscopy coupled to scanning spreading resistance microscopy gives insights to a layer-by-layer growth of SrVO3 (SVO) on NS, a 3D growth on uncovered part with NS, and an onset of crystallization of SVO on glass promoted by thickness. On the other hand, the examined optical properties reveal a transparency improvement when the thickness decreases. These eminent results allow to understand the growth process and the integration of functional oxides on NS, opening up new perspectives to tune the properties of vanadate films as transparent electrodes. The second approach is the combinatorial substrate epitaxy, where a polycrystalline SrTiO3 substrate was synthesized and characterized using macroscopic and local techniques. Similar macroscopic magnetic properties of polycrystalline La0.67Sr0.33MnO3 (LSMO) film were evidenced compared to single crystal substrate. Nevertheless, the submicronic LSMO magnetic properties investigated by magnetic force microscopy and Kerr magnetometry, revealed distinct magnetic response dependent on the grain orientation not observed in the case of single crystal STO substrate. This approach opens new perspectives to establish a library of orientation-functional property relationships in perovskites thin films.

Book Perovskite Oxide Thin Film Growth  Characterization  and Stability

Download or read book Perovskite Oxide Thin Film Growth Characterization and Stability written by Andrew Izumi and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies into a class of materials known as complex oxides have evoked a great deal of interest due to their unique magnetic, ferroelectric, and superconducting properties. In particular, materials with the ABO3 perovskite structure have highly tunable properties because of the high stability of the structure, which allows for large scale doping and strain. This also allows for a large selection of A and B cations and valences, which can further modify the material's electronic structure. Additionally, deposition of these materials as thin films and superlattices through techniques such as pulsed laser deposition (PLD) results in novel properties due to the reduced dimensionality of the material. The novel properties of perovskite oxide heterostructures can be traced to a several sources, including chemical intermixing, strain and defect formation, and electronic reconstruction. The correlations between microstructure and physical properties must be investigated by examining the physical and electronic structure of perovskites in order to understand this class of materials. Some perovskites can undergo phase changes due to temperature, electrical fields, and magnetic fields. In this work we investigated Nd0.5Sr0.5MnO3 (NSMO), which undergoes a first order magnetic and electronic transition at T=158K in bulk form. Above this temperature NSMO is a ferromagnetic metal, but transitions into an antiferromagnetic insulator as the temperature is decreased. This rapid transition has interesting potential in memory devices. However, when NSMO is deposited on (001)-oriented SrTiO3 (STO) or (001)-oriented (LaAlO3)0.3-(Sr2AlTaO6)0.7 (LSAT) substrates, this transition is lost. It has has been reported in the literature that depositing NSMO on (110)-oriented STO allows for the transition to reemerge due to the partial epitaxial growth, where the NSMO film is strained along the [001] surface axis and partially relaxed along the [11̄0] surface axis. This allows the NSMO film enough freedom of movement to undergo a shear strain along the [11̄0] axes, allowing the NSMO film to switch phases. It was found that the desired magnetic and electrical properties were closely tied to the structural properties, which were highly sensitive to the precise growth conditions. These perovskite oxides can be further geometrically constrained by patterning, resulting in additional novel magnetic and electrical properties. One such method of patterning involves implanting Ar into a film to locally destabilize the ordered perovskite structure, therefore suppress the magnetic and electrical properties. However, to fully integrate this technique into devices which require multi-planar processes, the ability for a patterned perovskite film to withstand high temperature anneals is crucial in creating more advanced structures. The stability of Ar-implanted La0.7Sr0.3MnO3 (LSMO) thin films was studied upon annealing at 400°C, 500°C, and 600°C. The LSMO retained its amorphous structure with little ferromagnetism after a 400°C anneal, but anneals at 500°C and 600°C resulted in partial recrystallization and a return of the ferromagnetic properties. This recrystallized film displayed semiconducting properties with a lower Curie temperature than the as deposited film. The deposition of an La0.7Sr0.3FeO3 (LSFO) film onto an Ar implanted LSMO film at 400°C caused the LSMO film to almost fully recrystallize, suggesting that the deposition process also recrystallizes the Ar-implanted film. In conclusion, two perovskites films were explored in this thesis. NSMO films proved to be very sensitive to growth conditions, and Ar-implanted LSMO films quickly recrystallized past 400°C or a subsequent film deposition. These studies provide useful information on the structural and electronic transformations these films go through during heat treatment and strain engineering.

Book Fundamentals of Perovskite Oxides

Download or read book Fundamentals of Perovskite Oxides written by Gibin George and published by CRC Press. This book was released on 2020-10-06 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook entitled Fundamentals of Perovskite Oxides: Synthesis, Structure, Properties and Applications summarizes the structure, synthesis routes, and potential applications of perovskite oxide materials. Since these perovskite-type ceramic materials offer opportunities in a wide range of fields of science and engineering, the chapters are broadly organized into four sections of perovskite-type oxide materials and technology. Covers recent developments in perovskite oxides Serves as a quick reference of perovskite oxides information Describes novel synthesis routes for nanostructured perovskites Discusses comprehensive details for various crystal structures, synthesis methods, properties, and applications Applies to academic education, scientific research, and industrial R&D for materials research in real-world applications like bioengineering, catalysis, energy conversion, energy storage, environmental engineering, and data storage and sensing This book serves as a handy and practical guideline suitable for students, engineers, and researchers working with advanced ceramic materials.

Book Structural Characterization of Perovskite Thin Films by X ray Reflectivity

Download or read book Structural Characterization of Perovskite Thin Films by X ray Reflectivity written by Jinyun He and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Perovskite oxides are a unique class of materials possessing a wide range of functional properties that stem from their spin, charge, lattice, and orbital degrees of freedom. The perovskite oxide exchange spring heterostructure, comprised of a hard and a soft magnetic layer, has similar properties to its metallic counterpart, but can be fine-tuned with intrinsic and extrinsic parameters such as chemical doping, lattice strain, and applied electric/magnetic fields. In this thesis, single layer La0.7Sr0.3CoO3 (LSCO) and La0.7Sr0.3MnO3 (LSMO) thin films on (LaAlO3)0.3(Sr2TaAlO6)0.7 (LSAT) substrates and bilayer LSCO/LSMO heterostructures on LSAT and NdGaO3 (NGO) substrates were grown by pulsed laser deposition. The magnetic properties of the samples were characterized by X-ray Absorption (XA) and X-ray magnetic circular dichroism (XMCD) and the structural properties were characterized by hard and soft X-ray Reflectivity (XRR). The XRR data measured at the Mn and Co L-edge energies were analyzed by fitting in the software ReMagX. Combined with the other techniques, the fitting of the XRR data was able to determine the best structural models for the samples, provide thickness and roughness values for each layer with a sub-Angstrom resolution, and aid in obtaining the optical constants of the materials. XRR was proved to be a powerful non-destructive technique in probing the structural profiles of the complex thin film heterostructures.

Book Perovskite Metal Oxides

Download or read book Perovskite Metal Oxides written by Srikanta Moharana and published by Elsevier. This book was released on 2023-05-30 with total page 730 pages. Available in PDF, EPUB and Kindle. Book excerpt: Perovskite Metal Oxides: Synthesis, Properties and Applications provides an overview on the topic, including the synthesis of various types of perovskites, their properties, characterization and application. The book reviews the applications of this category of materials for photovoltaics, electronics, biomedical, fuel cell, photocatalyst, sensor, energy storage and catalysis, along with processing techniques of perovskite metal oxides with a focus on low-cost and high-efficiency methods, including various properties and probable applications in academia and industry. Other sections discuss strategies to improve the functionality of perovskite metal oxide materials, including chemical methods and controlling the size, shape and structure of the materials. Finally, applications of perovskite metal oxides in energy conversion and storage, sensing and electronics are covered. Provides an overview of perovskite metal oxides, with an emphasis on synthesis, fabrication and characterization methods Discusses strategies to improve the functionality of perovskite metal oxide materials, including chemical methods and controlling the size, shape and structure of the materials Reviews applications of perovskite metal oxides in energy conversion and storage, sensing and electronics

Book Synthesis and Properties of Ferroelectric Perovskite Oxide Thin Films

Download or read book Synthesis and Properties of Ferroelectric Perovskite Oxide Thin Films written by Andrei Akbasheu and published by . This book was released on 2015 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: The growth of oxide thin films has long been of great interested for materials scientists for the application in advanced technologies such as nanoelectronics, photovoltaics and sensors. Atomic layer deposition (ALD) is known for being a non-expensive, low-vacuum and low-temperature deposition method able to conformally coat even high-aspect-ratio materials and structures. ALD has been mainly applied to prepare binary oxides such as ZnO and TiO2, and the synthesis of functional complex oxides such as BiFeO3 and CoFe2O4 has little been studied. In the first part of this work, the application of ALD to the preparation of complex oxide thin films based on the Bi-Fe-O system is explored. The important aspects of the ALD approach such as (a) the growth of amorphous Bi-Fe-O by ALD, (b) the epitaxial crystallization of the multiferroic perovskite BiFeO3 films on different substrates, (c) appearance of impurity phases in the films are addressed. Ultimately, the dissertation aims at dispelling the widely held notion that atomic layer deposition is not appropriate for attaining high-quality chemically complex oxide films in the epitaxial form, demonstrating the applicability as an inexpensive, facile, and highly scalable route. The second part of this work is devoted to the preparation and characterization of new ferroelectric thin films as photovoltaic materials. Large optical band gaps of ferroelectric oxides make the optical absorption impractical for solar cell applications. Recently a new strategy for band gap lowering by doping the perovskite KNbO3 with Ba on the A-site and Ni on the B-site resulting in the generation of Ni2+-O vacancy pairs has been shown to significantly increase the optical absorption without loss of ferroelectricity. Using pulsed laser deposition, the synthesis approach to thin films of these new oxides was developed despite significant challenges for the stoichiometry control. The chemical doping approach to the reduction of the band gap was extended to produce new visible-light-absorbing ferroelectric thin films in another perovskite oxide. These materials showed a switchable photovoltaic effect under the visible light illumination along with the retention of the ferroelectric order. This dissertation demonstrates the feasibility of thin film deposition of aforementioned doped ferroelectric oxide perovskites and their ferroelectric photovoltaic properties, which can be extended to other ferroelectric oxides, and provide important information on the synthesis of such materials as thin films.

Book Perovskites and Related Mixed Oxides

Download or read book Perovskites and Related Mixed Oxides written by Pascal Granger and published by John Wiley & Sons. This book was released on 2016-02-23 with total page 1050 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive handbook and ready reference details all the main achievements in the field of perovskite-based and related mixed-oxide materials. The authors discuss, in an unbiased manner, the potentials as well as the challenges related to their use, thus offering new perspectives for research and development on both an academic and industrial level. The first volume begins by summarizing the different synthesis routes from molten salts at high temperatures to colloidal crystal template methods, before going on to focus on the physical properties of the resulting materials and their related applications in the fields of electronics, energy harvesting, and storage as well as electromechanics and superconductivity. The second volume is dedicated to the catalytic applications of perovskites and related mixed oxides, including, but not limited to total oxidation of hydrocarbons, dry reforming of methane and denitrogenation. The concluding section deals with the development of chemical reactors and novel perovskite-based applications, such as fuel cells and high-performance ceramic membranes. Throughout, the contributions clearly point out the intimate links between structure, properties and applications of these materials, making this an invaluable tool for materials scientists and for catalytic and physical chemists.

Book Strain Controlled Functionalities in Lightly Doped Manganite Perovskite Epitaxial Thin Films Grown by Pulsed Laser Deposition

Download or read book Strain Controlled Functionalities in Lightly Doped Manganite Perovskite Epitaxial Thin Films Grown by Pulsed Laser Deposition written by Richard Teboh Mbatang and published by . This book was released on 2018 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Functional Oxides have been widely studied in the last decades because of their fascinating properties as ferromagnetism, ferroelectricity, superconductivity and multiferroicity. The widely studied complex oxides are the perovskite and the hexagonal oxides. Intriguing phenomena have been observed in epitaxial thin films of manganite perovskites, which greatly differed from those of bulk material. Some of the interesting properties of lightly doped manganite oxide thin films, especially La0.9Sr0.1MnO3 thin films, are an enhanced magnetoresistance (MR) and temperature coefficient of resistance (TCR). The physical properties of these films are related to the effects that occur at the interface. Some of these interfacial effects includes defect formation, charge transfer, exchange coupling, strain, interfacial reconstruction and cation intermixing. The fast development of new characterization techniques have made the study of interfacial effects easy. Fabrication techniques such as Pulsed Laser Deposition (PLD) have been employed to produce interfaces with great atomic precision. Selecting materials with the right lattice mismatch and optimization of the growth conditions as laser repetition rate, temperature, oxygen pressure, substrate-target distance and laser energy are crucial in growth of epitaxial thin films for functional device application. In addition to these, selecting the right proposition of the various phase is important in achieving the right microstructure for composite films. The main focus of this dissertation is to investigate the relationship between structure and magneto-transport properties in lightly doped manganite perovskite thin films with the concentration on 10% strontium doped lathanum manganese oxide, La0.9Sr0.1MnO3 (LSMO) grown by Pulsed Laser Deposition (PLD). We grew films of different thicknesses (15 nm, 30 nm, 75 nm) and on different substrates ((001) LaAlO3 (LAO, (001) SrLaGaO4 (LSGO), (110), GdScO3 (DSO) and (110) GaScO3). We found that thinner films show highly enhanced magnetic and transport properties while thicker films exhibit low transport and magnetic properties due to strain relaxation. We also observed that compressive strain enhanced magnetic (saturation magnetization, Curie temperature (Tc)) and transport properties (metal-insulating transition (MIT), magnetoresistance (MR), temperature coefficient of resistance (TCR)). The enhancement of magnetic and transport properties were attributed to the suppression of Jahn-Teller distortion, electron-phonon coupling and the enhancement of double exchange coupling. In summary, strain can be used to tune the physical properties of expitaxial thin films for technological applications.

Book Properties and Applications of Perovskite Type Oxides

Download or read book Properties and Applications of Perovskite Type Oxides written by L.G. Tejuca and published by CRC Press. This book was released on 1992-12-22 with total page 401 pages. Available in PDF, EPUB and Kindle. Book excerpt: This reference offers an overview of the bulk and surface properties of perovskite-like structures, and provides the latest discussions on the applications of these materials and processes. It also introduces ceramic methods for the processing of perovskite-derived high Tc cuprates.;Examining every available procedure for synthesizing high-surface-area perovskite oxides, this book: delineates processing techniques for preparing perovskite-derived high-critical-temperature superconductors; illustrates the relevance of physiochemical methods to investigate bulk and surface structures of perovskite compounds; explicates the importance of surface composition in the context of catalytic behaviour; summarizes methods of changing stoichiometry; shows how to design perovskite oxides for a given purpose; reviews key solid-state properties; and presents the major applications.

Book Characterization of Perovskite Oxide semiconductor Heterostructures

Download or read book Characterization of Perovskite Oxide semiconductor Heterostructures written by HsinWei Wu and published by . This book was released on 2018 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integrated oxide/semiconductor heterostructures have attracted intense interest for device applications which require sharp interfaces and controlled defects. The research of this dissertation has focused on the characterization of perovskite oxide/oxide and oxide/semiconductor heterostructures, and the analysis of interfaces and defect structures, using scanning transmission electrom microscopy (STEM) and related techniques. The SrTiO3/Si system was initially studied to develop a basic understanding of the integration of perovskite oxides with semiconductors, and successful integration with abrupt interfaces was demonstrated. Defect analysis showed no misfit dislocations but only anti-phase boundaries (APBs) in the SrTiO3 (STO) films. Similar defects were later observed in other perovskite oxide heterostructures. Ferroelectric BaTiO3 (BTO) thin films deposited directly onto STO substrates, or STO buffer layers with Ge substrates, were grown by molecular beam epitaxy (MBE) in order to control the polarization orientation for field-effect transistors (FETs). STEM imaging and elemental mapping by electron energy-loss spectroscopy (EELS) showed structurally and chemically abrupt interfaces, and the BTO films retained the c-axis-oriented tetragonal structure for both BTO/STO and BTO/STO/Ge heterostructures. The polarization displacement in the BTO films of TiN/BTO/STO heterostructures was investigated. The Ti4+ atomic column displacements and lattice parameters were measured directly using HAADF images. A polarization gradient, which switched from upwards to downwards, was observed in the BTO thin film, and evidence was found for positively-charged oxygen vacancies. Heterostructures grown on Ge substrates by atomic layer deposition (ALD) were characterized and compared with MBE-grown samples. A two-step process was needed to overcome interlayer reaction at the beginning of ALD growth. A-site-rich oxide films with thicknesses of at least 2-nm had to be deposited and then crystallized before initiating deposition of the following perovskite oxide layer in order to suppress the formation of amorphous oxide layers on the Ge surface. BTO/STO/Ge, BTO/Ge, SrHfTiO3/Ge and SrZrO3/Ge thin films with excellent crystallinity were grown using this process. Metal-insulator-metal (MIM) heterostructures were fabricated as ferroelectric capacitors and then electrically stressed to the point of breakdown to correlate structural changes with electrical and physical properties. BaTiO3 on Nb:STO was patterned with different top metal electrodes by focused-ion-beam milling, Au/Ni liftoff, and an isolation-defined approach.

Book Growth Mechanism and Interface Effects on Microstructure of Perovskite type Barium Titanate based Epitaxial Films

Download or read book Growth Mechanism and Interface Effects on Microstructure of Perovskite type Barium Titanate based Epitaxial Films written by Jie He and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This work was motivated and focused on the growth mechanism, microstructures and interfaces of barium titanate, BaTiO3 (BTO), based epitaxial thin films. Transimission electron microscopy (TEM), high resolution TEM (HRTEM), electron diffraction (ED) have been mainly employed in this study for microstructure investigations of BTO-based epitaxial thin films with the assistance of other materials characterization methods, such as X-ray diffraction (XRD), atomic force microscopy (AFM), Nanoindentation testing, etc. As a basic studying model, epitaxial BTO films were first deposited on the (001) MgO substrate using RF magnetron sputtering to provide fundamental knowledge of the film growth for BTO based thin films. The epitaxial BTO films show a tetragonal crystal structure (a = 4.02 Å and c = 4.11 Å) with epitaxial nanodomains induced from the rough film/substrate interface due to the modification of the substrate surface characteristics (steps, terraces, and kinks) during the deposition process. Two new phases of - calculus [gamma]y (Ba10TiO26) and Hß (BaTi8O24) were formed on the MgO substrate using RF magnetron sputtering. The atomic structures of the two new phases were determined and examined. The [gamma]y phase has a monoclinic structure, Cm, a=16.49 Å̊̊, b=8.94 Å, c=3.94 Å, y=77°. The Hß phase has a monoclinic structure, Cm, a = 17.88̊Å̊, b = 7.21Å, c = 3.94 Å̊̊̊, y =82°. Both [gamma]y and Hß phases have four different oriented domains. The orientation relationship between domains and MgO substrate is discussed. Initail study shows that these new phases possess novel and interesting properties. The doped BTO films with different dopant (Sr2 and Zr4) fabricated using pulsed laser deposition (PLD) have been studied for doping effects, interface effects and film growth mechanism. The (Ba, Sr)TiO3 (BST) epitaxial films grown on 1.2° and 5.3° miscut substrates consist of lager commensurate domains, and correspondly show higher dielectric constant and dielectric tunability, and lower average modulus and hardness than those of the films grown on the 3.5° miscut substrate. The results suggest that the differences on the interfacial structure have a tremendous effect on the properties of the films. The investigation on epitaxial Ba(Zr, Ti)O3 (BZT) and 2% Mn doped Ba(Zr, Ti)O3 (Mn:BZT) thin films grown on MgO substrate revealed the formation of twin-coupled domains on the epilayer by sharing their {111}/{110} planes as common planes. The structure evolution from epilayer to nanopillars is accomplished by alternatively introducing {111} and {110} twin boundaries, resulting in gradual shrinking or enlarging of the lateral size of the epitaxial grains/twin coupled nanopillars. The formations of twin domains, sharing planes and structure transition mechasim have been discussed in detail. Eventually, the microstructures and layer interfaces of [Mn:BZT//Mn:BST]N multilayer films consisting of 2% Mn doped (Ba, Sr)TiO3 (Mn:BST) and Mn:BZT layers on MgO (001) substrates with various deposition rates, deposition period numbers N were studied to provide an integral view of the formation of multilayer films in BTO system. All the [Mn:BZT//Mn:BST]N multilayer films present epitaxial quality and induced {111}/{110} twin-coupled domains initially formed at different film thickness/layers. The film/substrate interface has an important role for the formation of twin domains and the proportion of twin domain structures in the entire films. The layer interfaces between Mn:BST and Mn:BZT with period compression and extension strains were observed and discussed. The microstructure evolution and structure-related nano-mechanical properties of the multilayer films have been systematically investigated.

Book A Study of Structure Induced Phase Phenomena in Perovskite Oxide Thin Films

Download or read book A Study of Structure Induced Phase Phenomena in Perovskite Oxide Thin Films written by Jason Lapano and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The three core tenants of materials science are theory, synthesis, and characterization. A solid theoretical framework is required for understanding of the problem at hand and using that knowledge to advance new areas of research. Synthesis of pristine materials is required to study the theory in a physical system and prevent misinterpretation of results. Complex structures and compositions are often the most interesting, and when defects and impurities are of interest, perfectly-imperfect samples are required which are often the most challenging to synthesize. Characterization of these materials is equally as important and complex, requiring careful sample preparation and experimental setups. Further, it is not always clear how to observe the property of scientific interest, and new characterization techniques must be developed. This dissertation focuses on using these three tenants to understand and advance the field of transition metal perovskite complex oxides using thin films of the incipient ferroelectrics CaTiO3 and SrTiO3 and antiferromagnetic Mott-Insulators LaVO3 and YVO3. The knowledge gained in this thesis can be applied to other complex oxide materials in better understanding magnetic and electronic transitions, high Tc superconductivity and quantum hall effect. Coupled with the relatively simple structure and ease of integration of multiple different chemical compounds into a single heterostructure leads to near numerous avenues to design functionality into materials.The first sections of this thesis begin with (1) an introduction to the basic science and past work in perovskite oxides, followed by (2) exploring the most common and promising synthesis routes, and finally (3) the various characterization methods used. The 4th chapter addresses the specific challenges of growth of ternary complex oxide thin films in an industrially profitable fashion. The three primary criterion that these deposition methods must adhere to is that they must (a) control film stoichiometry to less than 1% deviations, (b) deposit conformal coatings over standard 8 silicon wafers, (c) and exhibit deposition rates in excess of 1 m/hr. We show that these can be achieved using a hybrid molecular beam (hMBE) epitaxy approach and outline a route for commercially viable growth of complex oxides on silicon. This method is applied directly to the deposition of SrTiO3 on silicon for virtual single crystal perovskite substrates. The 5th chapter of this thesis discusses the effect of epitaxial strain, stoichiometry and interfacial coupling in heterostructures of complex oxides. In the (SrTiO3)n(CaTiO3)n series of superlattices grown by hMBE, it is found that interfacial energies play a large role in dictating the macroscopic properties, particularly ferroelectricity. In coherently strained thin films, both CaTiO3 and SrTiO3 exhibit relaxor-like ferroelectric behavior below room temperature. However, certain superlattices of these materials show nonpolar behavior when probed using second harmonic generation (SHG). High resolution scanning transmission electron microscopy (STEM) reveals that the symmetry in the superlattice is different from the individual parent compounds at the same strain state. It is found these are directly related to the high density of interfacial layers present in the films. Further, interfacial mixing of the constituent layers on certain superlattices leads to the development of a Ca1-xSrxTiO3 alloy which develops a ferroelectric moment at low temperatures, leading to spurious SHG signals. The findings of this experiment highlight the sensitivity of these complex layered structures to strain, stoichiometry, distortion coupling effects, and interfacial mixing.

Book Ferroelectric Materials for Energy Applications

Download or read book Ferroelectric Materials for Energy Applications written by Haitao Huang and published by John Wiley & Sons. This book was released on 2019-01-04 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a comprehensive overview of the emerging applications of ferroelectric materials in energy harvesting and storage Conventional ferroelectric materials are normally used in sensors and actuators, memory devices, and field effect transistors, etc. Recent progress in this area showed that ferroelectric materials can harvest energy from multiple sources including mechanical energy, thermal fluctuations, and light. This book gives a complete summary of the novel energy-related applications of ferroelectric materials?and reviews both the recent advances as well as the future perspectives in this field. Beginning with the fundamentals of ferroelectric materials, Ferroelectric Materials for Energy Applications offers in-depth chapter coverage of: piezoelectric energy generation; ferroelectric photovoltaics; organic-inorganic hybrid perovskites for solar energy conversion; ferroelectric ceramics and thin films in electric energy storage; ferroelectric polymer composites in electric energy storage; pyroelectric energy harvesting; ferroelectrics in electrocaloric cooling; ferroelectric in photocatalysis; and first-principles calculations on ferroelectrics for energy applications. -Covers a highly application-oriented subject with great potential for energy conversion and storage applications. -Focused toward a large, interdisciplinary group consisting of material scientists, solid state physicists, engineering scientists, and industrial researchers -Edited by the "father of integrated ferroelectrics" Ferroelectric Materials for Energy Applications is an excellent book for researchers working on ferroelectric materials and energy materials, as well as engineers looking to broaden their view of the field.

Book Electrical   Electronics Abstracts

Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 2304 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Perovskite

    Book Details:
  • Author : Jinghua Zhang
  • Publisher : Nova Science Publishers
  • Release : 2013
  • ISBN : 9781624178009
  • Pages : 0 pages

Download or read book Perovskite written by Jinghua Zhang and published by Nova Science Publishers. This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, the authors present current research in the study of the crystallography, chemistry and catalytic performance of perovskites. Topics discussed include the defect structure and defect-induced expansion of perovskite oxides; perovskite-based catalysts for transformation of natural gas and oxygenates into syngas; Bi containing multiferroic perovskite oxide thin films; perovskites as catalysts for environmental remediation; microwave-assisted synthesis and characterisation of perovskite oxides; perovskite and lead based ceramic materials; photocatalytic properties of perovskite-type layered oxides; structure of perovskite electron-ionic conductors; and distorted perovskites.

Book Thin Film Growth and Deposition of Functional Perovskite Oxides

Download or read book Thin Film Growth and Deposition of Functional Perovskite Oxides written by Bryce Isaiah Edmondson and published by . This book was released on 2019 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research documented in this work focuses on the growth and deposition of thin film perovskite oxides for their electronic and photonic functionalities. The ever increasing demand for faster electronic devices, particularly in the realm of micro and nanoelectronics, is requiring diversification of the materials used in typical semiconductor-based integrated circuits. Metal oxides, particularly those in the perovskite family of materials, offers a wide range of functionalities that can both increase device performance and add new capabilities such as optical interconnects. The process in which perovskite oxide thin films are deposited and integrated with one another and conventional semiconductors can have many effects on the properties of the resulting device. This work explores these effects in the context of BaTiO3 (BTO) and Ba [subscript x] Sr1- [subscript x] TiO3 (BST) second order nonlinear optical effects, which includes second harmonic generation (SHG) and the linear electro-optic effect (Pockels effect). The work also studies the growth effects on the apparent interfacial conductivity of LaTiO3/SrTiO3 (LTO/STO) heterostructures. BTO thin films grown epitaxially on STO(001) by molecular beam epitaxy (MBE) experience strain relaxation due to misfit dislocations for increasing thickness while epitaxial BST thin films remain strained at equivalent thicknesses due to the smaller lattice mismatch. These strained BST films exhibit larger second harmonic generation than relaxed BTO films, for particular compositions, suggesting that the epitaxial strain enhances their polarization and second order nonlinear susceptibility beyond what is capable in equivalently thick, relaxed BTO films. We also explore the deposition of BTO and BST thin films by a chemical solution method under atmospheric conditions. The films are epitaxial with STO(001) template layers prepared by MBE on Si(001) wafers. Presence of the Pockels effect is confirmed in the films, although optical hysteresis and remanent polarization is not observed owing to the films' small (10-100 nm) grain size, structural defects, and residual tensile stress. Effective Pockels coefficients decrease monotonically with decreasing Ba composition. Non-zero Pockels response is observed in even Sr-rich films, which is explained by the tensile stress that deforms the normally cubic crystal structure into a non-centrosymmetric structure. Post-deposition annealing can increase the Pockels response by approximately four times and is attributed to an increase in grain size and the elimination of structural defects. Finally, we study the effects of oxygen vacancies caused by varying MBE growth conditions of LTO thin films on STO(001) single crystals and thin STO layers on Ge(001). Electrical conductivity of the heterostructures is LTO-thickness dependent, and LTO growth on STO/Ge structures requires orders of magnitude higher partial pressures of molecular oxygen in order to achieve crystalline LTO with proper oxidation states. This is explained by the propensity of LTO to scavenge oxygen from STO during growth, which is limited in LTO/STO/Ge heterostructures, and generates many free carriers and leads to the observed conductivity of the LTO/STO systems

Book Revolution of Perovskite

Download or read book Revolution of Perovskite written by Narayanasamy Sabari Arul and published by Springer Nature. This book was released on 2020-01-03 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents advanced synthesis techniques for fabricating Perovskite materials with enhanced properties for applications such as energy storage devices, photovoltaics, electrocatalysis, electronic devices, photocatalysts, sensing, and biomedical instruments. The book attempts to fill a gap in the published literature and provide a detailed reference on Perovskite materials. This book will be of use to graduate students and academic and industrial researchers in the fields of solid-state chemistry, physics, materials science, and chemical engineering.