Complex oxides present a fertile ground states of spin, lattice, orbital, and charge degree of freedom. The competition and interaction among different degrees of freedom provide a fascinating playground for fundamental scientific research as well as exploring applications in modern technologies. The scope of materials research has gone beyond understanding materials behaviors in ground states, and has extended to engineering new properties into materials and exploring possible hidden phases. There are static and dynamic approaches can be utilized to drive a material away from its ground state. Statically, by engineering complex oxides into heterostructures, the strain epitaxy effect can significantly alter the properties of the epitaxially grown films. In addition, tilt epitaxy promises an even more powerful route to directly control materials properties through a ubiquitous distortion in complex oxides. However, the characterization of tilt epitaxy is still challenging. The dynamic approach based on the idea of mode-selective pumping using ultrafast optical pulses, which can transiently drive a material away from its ground state by exciting a particular degree of freedom. Combining with delayed probe pulses, the dynamic trajectories of materials can be mapped out at femtosecond temporal resolution. Chapter 2 adopts the static approach following the scheme of tilt epitaxy. This chapter explores the paradigm of tilt epitaxy in thin films and demonstrates the non-destructively characterizing such epitaxy in three-dimensions for low symmetry complex tilt systems composed of light anions. More specifically, this chapter demonstrates that the interfacial tilt epitaxy can transform ultrathin calcium titanate, a non-polar earth-abundant mineral, into high-temperature polar oxides that last above 900 K. The comprehensive picture of octahedral tilts and polar distortions is revealed by reconstructing the three-dimensional electron density maps across film-substrate interfaces with atomic resolution using coherent Bragg rod analysis. The results are complemented with aberration-corrected transmission electron microscopy, film superstructure reflections, and are in excellent agreement with density functional theory. The study could serve as a broader template for non-destructive, three-dimensional atomic resolution probing of complex low symmetry functional interfaces. Chapter 3 turns to dynamic modulation the ground state of Ca3Ru2O7, which exhibits a rich phase diagram including two magnetic transitions (TN=56 K and TC=48 K) with the appearance of an insulating-like pseudogap (at TC). In addition, there is a crossover back to metallic behavior at T*=30 K, the origin of which is still under debate. This chapter applies ultrafast optical pump optical probe spectroscopy to investigate quasi-particle dynamics as a function of temperature in this enigmatic quantum material. Two dynamical processes are identified, both of which are influenced by the onset of the pseudogap. This includes electron-phonon relaxation and, below TC, the onset of a phonon bottleneck hindering the relaxation of quasiparticles across the pseudogap. A gap-modified two-temperature model is introduced to describe the temperature dependence of electron-phonon thermalization, and use the Rothwarf-Taylor to model the phonon bottleneck. In conjunction with density functional theory, the experimental results synergistically reveal the origin of the T-dependent pseudogap. Further, the data and analysis indicate that T* emerges as a natural consequence of T-dependent gapping out of carriers, and does not correspond to a separate electronic transition. The results highlight the value of low fluence ultrafast optics as a sensitive probe of low energy electronic structure, thermodynamic parameters, and transport properties of quantum materials. Chapter 4 serves as a comprehensive technical review of coherent Bragg rods analysis. This chapter starts with a mathematical description of the COBRA method and related iteration algorithms. Technical details being discussed includes: experimental data processing, symmetry application, convergence discussion, choice of boundary condition, sample thickness, and error analysis. The newly developed MATLAB routines for COBRA is introduced in appendix. Chapter 5 is a summary of the thesis and contains possible future directions.

This book provides the first complete and up-to-date summary of the state of the art in HAXPES and motivates readers to harness its powerful capabilities in their own research. The chapters are written by experts. They include historical work, modern instrumentation, theory and applications. This book spans from physics to chemistry and materials science and engineering. In consideration of the rapid development of the technique, several chapters include highlights illustrating future opportunities as well.

Comprehensive Inorganic Chemistry II, Nine Volume Set reviews and examines topics of relevance to today’s inorganic chemists. Covering more interdisciplinary and high impact areas, Comprehensive Inorganic Chemistry II includes biological inorganic chemistry, solid state chemistry, materials chemistry, and nanoscience. The work is designed to follow on, with a different viewpoint and format, from our 1973 work, Comprehensive Inorganic Chemistry, edited by Bailar, Emeléus, Nyholm, and Trotman-Dickenson, which has received over 2,000 citations. The new work will also complement other recent Elsevier works in this area, Comprehensive Coordination Chemistry and Comprehensive Organometallic Chemistry, to form a trio of works covering the whole of modern inorganic chemistry. Chapters are designed to provide a valuable, long-standing scientific resource for both advanced students new to an area and researchers who need further background or answers to a particular problem on the elements, their compounds, or applications. Chapters are written by teams of leading experts, under the guidance of the Volume Editors and the Editors-in-Chief. The articles are written at a level that allows undergraduate students to understand the material, while providing active researchers with a ready reference resource for information in the field. The chapters will not provide basic data on the elements, which is available from many sources (and the original work), but instead concentrate on applications of the elements and their compounds. Provides a comprehensive review which serves to put many advances in perspective and allows the reader to make connections to related fields, such as: biological inorganic chemistry, materials chemistry, solid state chemistry and nanoscience Inorganic chemistry is rapidly developing, which brings about the need for a reference resource such as this that summarise recent developments and simultaneously provide background information Forms the new definitive source for researchers interested in elements and their applications; completely replacing the highly cited first edition, which published in 1973

This book presents the latest developments in Femtosecond Chemistry and Physics for the study of ultrafast photo-induced molecular processes. Molecular systems, from the simplest H2 molecule to polymers or biological macromolecules, constitute central objects of interest for Physics, Chemistry and Biology, and despite the broad range of phenomena that they exhibit, they share some common behaviors. One of the most significant of those is that many of the processes involving chemical transformation (nuclear reorganization, bond breaking, bond making) take place in an extraordinarily short time, in or around the femtosecond temporal scale (1 fs = 10-15 s). A number of experimental approaches - very particularly the developments in the generation and manipulation of ultrashort laser pulses - coupled with theoretical progress, provide the ultrafast scientist with powerful tools to understand matter and its interaction with light, at this spatial and temporal scale. This book is an attempt to reunite some of the state-of-the-art research that is being carried out in the field of ultrafast molecular science, from theoretical developments, through new phenomena induced by intense laser fields, to the latest techniques applied to the study of molecular dynamics.

The Bulletin of the Atomic Scientists is the premier public resource on scientific and technological developments that impact global security. Founded by Manhattan Project Scientists, the Bulletin's iconic "Doomsday Clock" stimulates solutions for a safer world.