Principles of Magnetic Resonance

Transcription

1 С. Р. Slichter Principles of Magnetic Resonance Third Enlarged and Updated Edition With 185 Figures Springer-Verlag Berlin Heidelberg New York London Paris Tokyo Hong Kong

2 Contents 1. Elements of Resonance Introduction Simple Resonance Theory Absorption of Energy and Spin-Lattice Relaxation 4 2. Basic Theory Motion of Isolated Spins-Classical Treatment Quantum Mechanical Description of Spin in a Static Field Equations of Motion of the Expectation Value Effect of Alternating Magnetic Fields Exponential Operators Quantum Mechanical Treatment of a Rotating Magnetic Field Bloch Equations Solution of the Bloch Equations for Low H\ Spin Echoes Quantum Mechanical Treatment of the Spin Echo Relationship Between Transient and Steady-State Response of a System and of the Real and Imaginary Parts of the Susceptibility Atomic Theory of Absorption and Dispersion Magnetic Dipolar Broadening of Rigid Lattices Introduction Basic Interaction Method of Moments Example of the Use of Second Moments Magnetic Interactions of Nuclei with Electrons Introduction Experimental Facts About Chemical Shifts Quenching of Orbital Motion Formal Theory of Chemical Shifts Computation of Current Density Electron Spin Interaction Knight Shift 113 VII

3 4.8 Single Crystal Spectra Second-Order Spin Effects-Indirect Nuclear Coupling Spin-Lattice Relaxation and Motional Narrowing of Resonance Lines Introduction Relaxation of a System Described by a Spin Temperature Relaxation of Nuclei in a Metal Density Matrix-General Equations The Rotating Coordinate Transformation Spin Echoes Using the Density Matrix The Response to a ^-Function The Response to a 7r/2 Pulse: Fourier Transform NMR The Density Matrix of a Two-Level System Density Matrix-An Introductory Example Bloch-Wangsness-Redfield Theory Example of Redfield Theory Effect of Applied Alternating Fields Spin Temperature in Magnetism and in Magnetic Resonance Introduction A Prediction from the Bloch Equations The Concept of Spin Temperature in the Laboratory Frame in the Absence of Alternating Magnetic Fields Adiabatic and Sudden Changes Magnetic Resonance and Saturation Redfield Theory Neglecting Lattice Coupling Adiabatic Demagnetization in the Rotating Frame Sudden Pulsing The Approach to Equilibrium for Weak H\ Conditions for Validity of the Redfield Hypothesis Spin-Lattice Effects Spin Locking, T\ e, and Slow Motion Double Resonance What Is Double Resonance and Why Do It? Basic Elements of the Overhauser-Pound Family of Double Resonance Energy Levels and Transitions of a Model System The Overhauser Effect The Overhauser Effect in Liquids: The Nuclear Overhauser Effect Polarization by Forbidden Transitions: The Solid Effect Electron-Nuclear Double Resonance (ENDOR) 266 VIII

4 7.8 Bloembergen's Three-Level Maser The Problem of Sensitivity Cross-Relaxation Double Resonance The Bloembergen-Sorokin Experiment Hahn's Ingenious Concept The Quantum Description The Mixing Cycle and Its Equations Energy and Entropy The Effects of Spin-Lattice Relaxation The Pines-Gibby-Waugh Method of Cross Polarization Spin-Coherence Double Resonance-Introduction A Model System-An Elementary Experiment: The S-Flip-Only Echo Spin Decoupling Spin Echo Double Resonance Two-Dimensional FT Spectra-The Basic Concept Two-Dimensional FT Spectra-Line Shapes Formal Theoretical Apparatus I-The Time Development of the Density Matrix Coherence Transfer Formal Theoretical Apparatus II-The Product Operator Method The Jeener Shift Correlation (COSY) Experiment Magnetic Resonance Imaging Advanced Concepts in Pulsed Magnetic Resonance Introduction The Carr-Purcell Sequence The Phase Alternation and Meiboom-Gill Methods Refocusing Dipolar Coupling Solid Echoes The Jeener-Broekaert Sequence for Creating Dipolar Order The Magic Angle in the Rotating Frame- The Lee-Goldburg Experiment Magic Echoes Magic Angle Spinning The Relation of Spin-Flip Narrowing to Motional Narrowing The Formal Description of Spin-Flip Narrowing Observation of the Spin-Flip Narrowing Real Pulses and Sequences Avoiding a 2-Axis Rotation Nonideality of Pulses " Analysis of and More Uses for Pulse Sequence 423 IX

5 9. Multiple Quantum Coherence Introduction The Feasibility of Generating Multiple Quantum Coherence- Frequency Selective Pumping Nonselective Excitation The Need for Nonselective Excitation Generating Multiple Quantum Coherence Evolution, Mixing, and Detection of Multiple Quantum Coherence Three or More Spins Selecting the Signal of a Particular Order of Coherence High Orders of Coherence Generating a Desired Order of Coherence Mixing to Detect High Orders of Coherence Electric Quadrupole Effects Introduction Quadrupole Hamiltonian-Part Clebsch-Gordan Coefficients, Irreducible Tensor Operators, and the Wigner-Eckart Theorem Quadrupole Hamiltonian-Part Examples at Strong and Weak Magnetic Fields Computation of Field Gradients Electron Spin Resonance Introduction Example of Spin-Orbit Coupling and Crystalline Fields Hyperfine Structure Electron Spin Echoes V k Center Summary 555 Problems 557 Appendixes 579 X A. A Theorem About Exponential Operators 579 B. Some Further Expressions for the Susceptibility 580 С Derivation of the Correlation Function for a Field That Jumps Randomly Between ±/io 584 D. A Theorem from Perturbation Theory 585 E. The High Temperature Approximation 589 F. The Effects of Changing the Precession Frequency- Using NMR to Study Rate Phenomena 592

6 G. Diffusion in an Inhomogeneous Magnetic Field 597 H. The Equivalence of Three Quantum Mechanics Problems 601 I. Powder Patterns 605 J. Time-Dependent Hamiltonians 616 K. Correction Terms in Average Hamiltönian Theory- The Magnus Expansion 623 Selected Bibliography 629 References 639 Author Index 647 Subject Index 651 XI