Download or read book High Temperature Magnetic Properties of Transition Metal Oxides with Perovskite Structure written by Dinesh Baskar and published by . This book was released on 2008 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis Characterization and Magnetic Properties of Fe Doped ReCrO3 Re Pr Sm La Perovskites written by Bakshi Venugopal Rao and published by Mohammed Abdul Malik. This book was released on 2024-03-11 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Perovskite materials with a general formula ABO3 exhibit rich and varying physical properties including magnetic, semi-conducting, ferroelectric, multiferroic. Thus it is interesting and meaningful in both theory and experiments of these materials. In ABO3 structure, the zero occupancy of the transition metal B cations are chemically known to favour ferroelectricity. The availability of the transition metal d electrons in the perovskite oxides are necessary for magnetism to reduce the tendency for off centering ferroelectric distortions. Hence ferromagnetism and ferroelectricity seem to be mutually exclusive in perovskite structure oxides and the scarcity of ferromagnetic and ferroelectric materials has stimulated many theoretical and experimental works. A few metal oxides are known to exhibit ferroelectricity at relatively high temperatures and a magnetic transition at lower temperatures. Recently some researchers have found that rare earth chromites with formula ReCrO3 exhibit canted anti ferromagnetic [TN=113-140 K] and dielectric [TC=472-516K] transition characteristic which is a kind of possible multiferroic behavior. From the above discussion it is clear that the importance of the perovskite structure which has a stable and standard structure and also the transition metal oxides as a possible important application as a multiferroic materials. In particular, the rare earth transition metal oxides from the perovskite family are well known due to their striking properties which are related to exchange mechanisms and the competition between ferromagnetic and anti-ferromagnetic phases
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 Investigation of Structural and Magnetic Properties of Perovskite Type Oxides Containing 5d Ions written by Jie Xiong and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of this thesis work is to explore the exotic magnetism in perovskite type oxide materials containing 5d transition metal. Strong spin orbit coupling and extended 5d orbitals lay the foundation of unique orbital and spin interactions between 5d ions. Understanding the physics of 5d ions is not only of fundamental interests, but important in the search for new phases of matter such as topological insulators, Weyl semimetals and quantum spin liquids. Chapter 2 and 3 discuss the magnetic behavior of 5d1 and 5d2 ions on a face-centered cubic lattice embedded in the double perovskite structure. The crystal structure, transport and magnetic properties of double perovskites Ba2BReO6 (B=Cd, Zn, Sc, In, Lu, La), Sr2LuReO6 and Ca2ScReO6 are characterized by X-ray diffraction, neutron diffraction, dc electric conductivity, dc magnetometry and heat capacity. Ferromagnetic ground states are prevalent in 5d1 systems. Orbital degree of freedom dominates the magnetic behavior over a wide temperature range before the magnetic ordering, resulting in changing effective moments with temperature and artificial negative Weiss constants. The ground state is a delicate balance sensitive to factors such as spin orbit coupling, metal-oxygen covalency, and subtle structural details. On the other hand, 5d2 systems are dominated by antiferromagnetic ground states. Filling d orbitals on the diamagnetic ion tends to destroy long range magnetic ordering in compounds with cubic symmetry. Strong distortion of the octahedral environment of 5d2 ions can result in ionic singlet states, which is not possible in 5d1 systems. Chapter 4 investigates the superexchange coupling between 5d ions and 3d ions in ordered double perovskites Sr2-xCaxCoOsO6. The crystal structures and magnetic properties are characterized using X-ray diffraction, neutron diffraction and magnetometry. Independent magnetic ordering of Co and Os sublattices are found in Sr-heavy compounds with less structural distortions, stabilized by Co-Co interactions (Co-O-O-Co and Co-O-Os-O-Co superexchange coupling) and Os-Os interactions (Os-O-O-Os and Os-O-Co-O-Os superexchange coupling), respectively. The Os-Os interactions are more sensitive to structural distortions than the Co-Co interactions. As a result, magnetic ordering of the Os sublattice disappear at lower Ca doping level than that of the Co sublattice. The strength of Co-Os superexchange coupling increases as the structure gets more distorted, resulting in ferrimagnetic ordering between Co and Os sublattices on the Ca-heavy compound. Complex glassy behavior is present in a wide compositional range in between due to the presence of competing magnetic interactions.
Download or read book High Pressure Materials Properties Magnetic Properties of Oxides Under Pressure written by Yoshiyuki Kawazoe and published by Springer Nature. This book was released on 2023-08-14 with total page 774 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject of this supplement to Landolt-Börnstein IV/22 Series is to present both the numerical and graphical data on the various magnetic properties of materials under pressure. Data for transition metal binary oxides MmOn [M: transition metals, O: oxygen, m, n: 1~15], MXO [M: transition metals, X: F, Cl, Br, O: oxygen] and MM’On [M: transition metals, M’: transition metals or non-transition metal elements, O: oxygen, n=2, 2.5, 3] ternary oxides are presented. As well known, the data-compiling principle in the Landolt-Bӧrrnstein series is to choose the best reliable values from many available experimental data. The present compilation is done according to this principle.
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 2000-10-17 with total page 404 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.
Download or read book Physics of Transition Metal Oxides written by Sadamichi Maekawa and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fact that magnetite (Fe304) was already known in the Greek era as a peculiar mineral is indicative of the long history of transition metal oxides as useful materials. The discovery of high-temperature superconductivity in 1986 has renewed interest in transition metal oxides. High-temperature su perconductors are all cuprates. Why is it? To answer to this question, we must understand the electronic states in the cuprates. Transition metal oxides are also familiar as magnets. They might be found stuck on the door of your kitchen refrigerator. Magnetic materials are valuable not only as magnets but as electronics materials. Manganites have received special attention recently because of their extremely large magnetoresistance, an effect so large that it is called colossal magnetoresistance (CMR). What is the difference between high-temperature superconducting cuprates and CMR manganites? Elements with incomplete d shells in the periodic table are called tran sition elements. Among them, the following eight elements with the atomic numbers from 22 to 29, i. e. , Ti, V, Cr, Mn, Fe, Co, Ni and Cu are the most im portant. These elements make compounds with oxygen and present a variety of properties. High-temperature superconductivity and CMR are examples. Most of the textbooks on magnetism discuss the magnetic properties of transition metal oxides. However, when one studies magnetism using tradi tional textbooks, one finds that the transport properties are not introduced in the initial stages.
Download or read book Localized to Itinerant Electronic Transition in Perovskite Oxides written by John B. Goodenough and published by Springer. This book was released on 2003-09-04 with total page 249 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interest in the transition metal oxides with perovskite related structures goes back to the 1950s when the sodium tungsten bronzes NaxWO3 were shown to be metallic [1], the system Lal_xSr~MnO3 was found to contain a ferromagnetic conductive phase [2], and La0.sSr0.sCoO3 was reported to be a ferromagnetic metal, but with a peculiar magnetization of 1.5 #a/Co atom [3]. Stoichiometric oxide perovskites have the generic formula AMO3 in which the A site is at the center of a simple cubic array of M sites; the oxide ions form (180 ° 4)) M O M bridges to give an MO3 array of corner shared MO6/2 octahedra and the larger A cations have twelvefold oxygen coordination. Mismatch between the A O and M O equilibrium bond lengths introduces internal stresses. A compressive stress on the MO3 array is accommodated by a lowering of the M O M bond angle from 180 ° to (180 ° 4)); a tensile stress on the M O M bonds is accommodated by the formation of hexagonal polytypes [4].
Download or read book High pressure Synthesis of the 4d and 5d Transition metal Oxides with the Perovskite and the Perovskite related Structure and Their Physical Properties written by Jinguang Cheng and published by . This book was released on 2010 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Walker-type multianvil high-pressure facility is capable of high-pressure syntheses and measurements beyond 10 GPa and has been utilized in my research to synthesize the 4d Ruthenium and Rhodium and the 5d Iridium oxides with the perovskite-related structures. Under high-pressure and high-temperature conditions, these families of oxides can be enlarged to a great extent so that enables us not only to address the long-standing problem about ferromagnetism in the perovskite ruthenates but also explore new phenomena associated with the structural and electronic properties in the iridates and rhodates. In the perovskite ruthenates ARuO3 (A= Ca, Sr, and Ba), a systematic study of the variations of the ferromagnetic transition temperature T[subscript c] and the critical isothermal magnetization as a function of the average A-site cation size and the size variance as well as external high pressures reveals explicitly the crucial role of the local lattice strain and disorder on T[subscript c] and the nature of the localized-electron ferromagnetism. However, such a steric effect is dominated by the electronic effect in another perovskite ruthenate PbRuO3, which is a paramagnetic metal down to 1.8 K and undergoes a first-order structural transition to a low-temperature Imma phase at Tt [almost equal to] 90 K. Bandwidth broadening due to orbital hybridization between Pb-6s and Ru-4d plays an important role in suppressing the ferromagnetism in the Sr1-zPbzRuO3 system. The high-pressure sequence of the 9R-BaIrO3 was explored and three more polytypes, i.e. 5H, 6H and 3C, were identified under 10 GPa. With increasing fraction of the corner- to face-sharing IrO6/2 octahedra, the ground states of BaIrO3 evolve from a ferromagnetic insulator with T[subscript c] [almost equal to] 180 K in the 9R phase to a ferromagnetic metal with T[subscript c] [almost equal to] 50 K in the 5H phase, and finally to an exchange-enhanced paramagnetic metal near a quantum critical point in the 6H phase. In addition to the perovskite SrRhO3, a new 6H polytype was synthesized for the first time under high pressure and a pressure-temperature phase diagram was given for the 6H-perovskite transformation. Restoration of the Curie-Weiss behavior in the high-temperature magnetic susceptibility [chi](T) of the perovskite SrRhO3 resolves the puzzle about unusual dependence of [chi]−1 [symbol] T2 reported earlier and highlights the importance of spin-orbit coupling in the 4d and 5d transition-metal oxides.
Download or read book Fundamentals of Perovskite Oxides written by Gibin George and published by CRC Press. This book was released on 2020-10-07 with total page 404 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.
Download or read book Electronically highly correlated ternary transition metal oxides written by Alexander Krimmel and published by diplom.de. This book was released on 2005-04-15 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction: Transition metal oxides represent a large class of compounds with a uniquely wide range of electronic properties. Some of these properties, like the magnetism of loadstone, have been known since antiquity. Others, like high-temperature superconductivity have been discovered only recently and indeed would have been thought of being impossible 20 years ago. Transition metal oxides may be good insulators, semiconductors, metals or superconductors. Many of them display a metal-to-insulator transition (MIT) as a function of an external control parameter (usually temperature, pressure or chemical composition). The differences of electrical conductivity are also reflected by drastic changes of other physical properties related to the electronic structure. The electrical, magnetic and optical properties of transition metal oxides find a rich field of important technical applications. A classical example is the wide use of ferrites in electronic devices. Further examples of suitable technological applications include wide gap semiconductors, superconductors and thermoelectric materials, to mention just a few. Apart from these exciting electronic properties, some transition metal oxides exhibit a remarkable mechanical and high-temperature stability together with a strong resistance against corrosion, thus forming ideal coating materials. Several transition metal oxides may also serve as catalysts. It was the discovery of high-temperature superconductivity in the cuprates and, subsequently, of the colossal magneto-resistance effect (CMR) in the manganates that triggered a tremendous research effort in transition metal oxides during the last decade. [...]
Download or read book Functional Metal Oxides written by Satishchandra Balkrishna Ogale and published by John Wiley & Sons. This book was released on 2013-11-08 with total page 478 pages. Available in PDF, EPUB and Kindle. Book excerpt: Functional oxides are used both as insulators and metallic conductors in key applications across all industrial sectors. This makes them attractive candidates in modern technology ? they make solar cells cheaper, computers more efficient and medical instrumentation more sensitive. Based on recent research, experts in the field describe novel materials, their properties and applications for energy systems, semiconductors, electronics, catalysts and thin films. This monograph is divided into 6 parts which allows the reader to find their topic of interest quickly and efficiently. * Magnetic Oxides * Dopants, Defects and Ferromagnetism in Metal Oxides * Ferroelectrics * Multiferroics * Interfaces and Magnetism * Devices and Applications This book is a valuable asset to materials scientists, solid state chemists, solid state physicists, as well as engineers in the electric and automotive industries.
Download or read book Properties Of Perovskites And Other Oxides written by Tom W Kool and published by World Scientific. This book was released on 2010-05-07 with total page 583 pages. Available in PDF, EPUB and Kindle. Book excerpt: “This collection of reprints allows the reader to chart the course of Müller's scientific development, from his early papers in the late 1950s all the way to high-temperature superconductivity in 1985 … A particular highlight is Müller's work on the Jahn-Teller effect … written in 1967 and appearing only as an article in a conference proceedings is a gem. Other treasures include the reviews on structural phase transitions (from 1981 and 1991, respectively) that are otherwise only obtainable in specialist books.”Contemporary PhysicsIn this book some 50 papers published by K A Müller as author or co-author over several decades, amplified by more recent work mainly by T W Kool with collaborators, are reproduced. The main subject is Electron Paramagnetic Resonance (EPR) applied to the study of perovskites and other oxides with related subjects. This wealth of papers is organized into eleven chapters, each with an introductory text written in the light of current understanding. The contributions of the first editor on structural phase transitions have been immense, and because K A Müller and J C Fayet have published a review paper on the subject, the latter is reproduced in chapter VII. Not related to EPR is a part of chapter VIII on the dipolar and quantum paraelectric behavior with dielectric studies. In chapter X two papers proving the existence of Fermi glasses are reproduced.The year 1986 bears some significance: early in this year the paper by Bednorz and Müller on the possible observation of superconductivity was published. This resulted in a substantial shift in the paradigm of condensed matter physics, to which the present first editor has contributed scientifically with others and which will be reviewed in a second volume.
Download or read book NBS Special Publication written by and published by . This book was released on 1978 with total page 790 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transition Metal Oxides written by P. A. Cox and published by Oxford University Press. This book was released on 2010-08-19 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition metal oxides form a series of compounds with a uniquely wide range of electronic properties. They have important applications as dielectrics,semiconductors, and metals, and as materials for magnetic and optical uses. The recent discovery of `high temperature' superconductors has brought the attention of a wide scientific community to this area and has highlighted the problems involved in trying to understand transition metal oxides. The present book is not primarily about Tc superconductors, although their main properties are discussed in the final sections. The main aim is to describe the varied electronic behaviour shown by transition metal oxides, and to discuss the different types of theoretical model that have been proposed to interpret it. It is intended to provide an introduction to this fascinating and difficult field, at a level suitable for graduate students and other research workers with a background in solid- state chemistry or physics.
Download or read book Properties of Perovskites and Other Oxides written by K. Alex Mller and published by World Scientific. This book was released on 2010 with total page 583 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book some 50 papers published by K A Müller as author or co-author over several decades, amplified by more recent work mainly by T W Kool with collaborators, are reproduced. The main subject is Electron Paramagnetic Resonance (EPR) applied to the study of perovskites and other oxides with related subjects. This wealth of papers is organized into eleven chapters, each with an introductory text written in the light of current understanding. The contributions of the first editor on structural phase transitions have been immense, and because K A Müller and J C Fayet have published a review paper on the subject, the latter is reproduced in chapter VII. Not related to EPR is a part of chapter VIII on the dipolar and quantum paraelectric behavior with dielectric studies. In chapter X two papers proving the existence of Fermi glasses are reproduced.The year 1986 bears some significance: early in this year the paper by Bednorz and Müller on the possible observation of superconductivity was published. This resulted in a substantial shift in the paradigm of condensed matter physics, to which the present first editor has contributed scientifically with others and which will be reviewed in a second volume.
Download or read book Physical Properties of Transition Metal Oxides Synthesized by Floating Zone Method and Spark Plasma Sintering written by Zongyao Li and published by . This book was released on 2018 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition metal oxides have attracted growing attention over the last few decades because of rich physical properties they exhibit. Perovskite structure transition metal oxides AMO3 are of particular interest to the design of functional materials in modern techniques, since a variety of ways can be used to tune the physical properties of AMO3. Single crystals of Y1− [subscript x] La [subscript x] TiO3 are grown by floating zone method to study the magnetic transition from ferromagnetic in YTiO3 to G-type antiferromagnetic in LaTiO3. Y1− [subscript x] La [subscript x] TiO3 shows similar magnetic phase diagram with RTiO3 family, and the magnetism and the transition temperature can be finely tuned by varying the La doping x. By measuring the change of magnetic transition temperatures on single crystal samples under uniaxial stress, the correlation between the lattice distortions and the cooperative orbital ordering can be distinguished. Double perovskite CaMnTi2O6 is the first columnar A-site ordered perovskite exhibiting ferroelectric property. Spark plasma sintering (SPS) is used to successfully synthesize gram-level Ca2− [subscript x] Mn [subscript x] Ti2O6, which has the same crystal structure and similar high-T [subscript c] ferroelectric property. Through neutron diffraction, the detailed information of the structure is obtained, and the driving force for ferroelectricity is identified. Inspired by the successful synthesis of double perovskite Ca2− [subscript x] Mn [subscript x] Ti2O6, perovskites La1− [subscript x] Pr [subscript x] RuO3 are obtained by SPS as well. The substitution of La by smaller rare earth ion Pr gives rise to the crossover from itinerant to localized electronic behavior. A systematical study of physical properties is made and an unusual second-order metal insulator transition is found in La1− [subscript x] Pr [subscript x] RuO3. The A2+V2O4 spinels have the smallest gap caused by electron-electron correlations in the single-valent spinels, and the V-V bond length in these spinels decreases as the A-site cation is replaced by cations in the order of A = Cd, Mn, Fe, Mg, Zn, Co. The density functional theory (DFT) calculation and transport properties of CoV2O4 under pressure indicate that CoV2O4 might be at the crossover between localized electron and itinerant electronic behavior. In order to clarify this, the series of AV2O4 spinels (A = Cd, Mn, Fe, Mg, Zn, Co) are studied with in situ high-pressure x-ray and neutron diffraction at different temperatures.
