Using the spin-Hamiltonian formalism the magnetic parameters are introduced through the components of the Lambda-tensor involving only the matrix elements of the angular momentum operator. The energy levels for a variety of spins are generated and the modeling of the magnetization, the magnetic susceptibility and the heat capacity is done. Theoretical formulae necessary in performing the energy level calculations for a multi-term system are prepared with the help of the irreducible tensor operator approach. The goal of the programming lies in the fact that the entire relevant matrix elements (electron repulsion, crystal field, spin-orbit interaction, orbital-Zeeman, and spin-Zeeman operators) are evaluated in the basis set of free-atom terms. The modeling of the zero-field splitting is done at three levels of sophistication. The spin-Hamiltonian formalism offers simple formulae for the magnetic parameters by evaluating the matrix elements of the angular momentum operator in the basis set of the crystal-field terms. The magnetic functions for dn complexes are modeled for a wide range of the crystal-field strengths.
Magnetochemistry is a highly interdisciplinary field that attracts the interest of chemists, physicists and material scientists. Although the general strategy of theoretical molecular magnetism has been in place for decades, its performance for extended systems of interacting magnetic units can be very complicated. Professor Boca's book treats the "mosaic" of the theoretical approaches currently used in the field. This book presents a review of the theoretical concepts of molecular magnetism. The first chapter of the book recapitulates the necessary mathematical background. An overview of macroscopic magnetic properties is then presented. Formulation of magnetic parameters and methods of their calculation are given, followed by a brief summary of magnetic behaviour. The core of the book deals with the temperature dependence of magnetic susceptibility for mononuclear complexes, dimers, and exchange-coupled clusters. This book will be particularly useful for those scientists and students working in the field of molecular magnetism who need to refer to a complete and systematic treatment of the mathematics of magneto-chemical theory.
Coordination chemistry is the study of compounds formed between metal ions and other neutral or negatively charged molecules. Coordination chemistry includes areas of inorganic solid state chemistry, organometallic chemistry and bioinorganic chemistry, as well as applications to analytical chemistry, catalysis, industrial chemistry and materials science.
Humans have been “manually” extracting patterns from data for centuries, but the increasing volume of data in modern times has called for more automatic approaches. Early methods of identifying patterns in data include Bayes’ theorem (1700s) and Regression analysis (1800s). The proliferation, ubiquity and incre- ing power of computer technology has increased data collection and storage. As data sets have grown in size and complexity, direct hands-on data analysis has - creasingly been augmented with indirect, automatic data processing. Data mining has been developed as the tool for extracting hidden patterns from data, by using computing power and applying new techniques and methodologies for knowledge discovery. This has been aided by other discoveries in computer science, such as Neural networks, Clustering, Genetic algorithms (1950s), Decision trees (1960s) and Support vector machines (1980s). Data mining commonlyinvolves four classes of tasks: • Classi cation: Arranges the data into prede ned groups. For example, an e-mail program might attempt to classify an e-mail as legitimate or spam. Common algorithmsinclude Nearest neighbor,Naive Bayes classi er and Neural network. • Clustering: Is like classi cation but the groups are not prede ned, so the algorithm will try to group similar items together. • Regression: Attempts to nd a function which models the data with the least error. A common method is to use Genetic Programming. • Association rule learning: Searches for relationships between variables. For example, a supermarket might gather data of what each customer buys.
This book presents critical reviews of the present position and future trends in modern chemical research concerned with chemical structure and bonding. It contains short and concise reports, each written by the world's renowned experts. Still valid and useful after 5 or 10 years, more information as well as the electronic version of the whole content is available at: springerlink.com.
Investigating the relationship between the magnetic properties and structure of molecules, molecular magnetochemistry, is an area of growing interest to scientists in a variety of fields, including physical, organic and inorganic chemistry, molecular physics, and biophysics. For the first time, systematic results on magnetic properties of molecules such as mean magnetic susceptibility, their anisotropies and principal magnetic axes are presented. Molecular Magnetochemistry is a comprehensive and up-to-date view on experimental methods not covered in previous volumes, including the Zeeman effect in vapor phase and magnetic birefringence of diamagnetic systems (Cotton-Mouton Effect). The relationship between magnetic and related electrical phenomena is also described, summing up experimental data on magnetic and electrical anisotropies and components of molecular quadrupole moments.
Magnetochemistry is concerned with the study of magnetic properties in materials. It investigates the relationship between the magnetic properties of chemical compounds and their atomic and molecular structure. This rapidly growing field has a number of applications, and the measuring and interpreting of magnetic properties is often conducted by scientists who are not specialists in the field. Magnetochemistry requires complex mathematics and physics and so can be daunting for those who have not previously studied it in depth. Aimed at providing a single source of information on magnetochemistry, this book offers a comprehensive and contemporary review of the mathematical background and formula for predicting or fitting magnetic data, including a summary of the theory behind magnetochemistry to help understand the necessary calculations. Along with tables listing the key formula, there is also a model of the magnetic functions showing the effect of individual magnetic parameters. The clear structure and comprehensive coverage of all aspects of magnetochemistry will make this an essential book for advanced students and practitioners. Provides comprehensive overview of the mathematical background of magnetochemistry Uses clear and accessible language so scientists in a variety of fields can utilize the information Detailed explanations of equations and formula
Spin Ladders and Spin Chains.- Probing Magnetic Phases in Different Systems.- Spin Glasses; From the Roots to the Present.- Magnetism in Nanostructures.- Surface and Interface Magnetism on the Atomic Scale.- Spectroscopy of Quantum Antiferromagnets.- Modern Methods for Investigating Magnetism.- Low Dimensionalmagnetism in Transition Metal Oxyborates.- Finite Temperature Half-metallic Ferromagnets.- Charge Order in Doped and Self-doped Oxides: Present Pictures.- Magnetic Tunnel Junctions Based on Half Metallic Oxides.- SrCu2 (BO3)2- a 2D Spin Gap Material.- Magnetism in Quantum Spin Systems.- Chemistry Aspects of Double Perovskites.- Magnetism in Carbon based Materials.- Microstructure Studies of Manganites by Lorentz-TEM Technique.- Local-Moment Systems: Ferromagnetism and Electronic Correlations.- Magnetism of Heavy Electron Materials.- Commenturate and Incommensurate Magnetism in Layered Antiferromagnets.- Single Crystals of Manganites and Related Materials.- Collossal Magnetoresistance and the Physics of Thin Maganite.- Dilute Magnetic Semiconductors.- Layed Co Oxides as a Thermoelectric Material.- New Magnetic Systems Exhibiting Superconductivity
Hardbound. The large and growing numbers of publications and patents in magnetism show that the last decade has witnessed a number of impressive discoveries important to both basic science and technology, and that magnetism is now in a new golden age. It is therefore an ideal time to provide an historical perspective of these developments, to identify the most important issues and to provide a perspective for developments anticipated in the beginning of the next century.The forty-six review articles in this book, while not exhaustive, summarize the most significant recent and ongoing exciting scientific and technological developments and provide both the flavor and meaning of magnetism as a vital field of importance to both basic science and device applications. The authors are all well known and respected authorities in their specific areas of expertise. The table of contents reflects the vitality and richness of the field.
Detailed reviews of new and emerging topics in chemical physics presented by leading experts The Advances in Chemical Physics series is dedicated to reviewing new and emerging topics as well as the latest developments in traditional areas of study in the field of chemical physics. Each volume features detailed comprehensive analyses coupled with individual points of view that integrate the many disciplines of science that are needed for a full understanding of chemical physics. Volume 153 of Advances in Chemical Physics features six expertly written contributions: Recent advances of ultrafast X-ray absorption spectroscopy for molecules in solution Scaling perspective on intramolecular vibrational energy flow: analogies, insights, and challenges Longest relaxation time of relaxation processes for classical and quantum Brownian motion in a potential escape rate theory approach Local fluctuations in solution: theory and applications Macroscopic effects of microscopic heterogeneity Ab initio methodology for pseudospin Hamiltonians of anisotropic magnetic centers Reviews published in Advances in Chemical Physics are typically longer than those published in journals, providing the space needed for readers to fully grasp the topic: the fundamentals as well as the latest discoveries, applications, and emerging avenues of research. Extensive cross-referencing enables readers to explore the primary research studies underlying each topic. Advances in Chemical Physics is ideal for introducing novices to topics in chemical physics. Moreover, the series provides the foundation needed for more experienced researchers to advance their own research studies and continue to expand the boundaries of our knowledge in chemical physics.
This book provides an overview of the physical phenomena discovered in magnetic molecular materials over the last 20 years. It is written by leading scientists having made the most important contributions to this active area of research. The main topics of this book are the principles of quantum tunneling and quantum coherence of single-molecule magnets (SMMs), phenomena which go beyond the physics of individual molecules, such as the collective behavior of arrays of SMMs, the physics of one-dimensional single–chain magnets and magnetism of SMMs grafted on substrates. The potential applications of these physical phenomena to classical and quantum information, communication technologies, and the emerging fields of molecular spintronics and magnetic refrigeration are stressed. The book is written for graduate students, researchers and non-experts in this field of research.