Page 120 - Academic Press Encyclopedia of Physical Science and Technology 3rd Analytical Chemistry

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Encyclopedia of Physical Science and Technology EN005E-212 June 15, 2001 20:32

Electron Spin Resonance

Larry Kevan
University of Houston

I. Basic Principles
II. Experimental Aspects
III. Isotropic Hyperfine Analysis
IV. Relation of Hyperfine Constants
to Spin Densities
V. Second-Order Hyperfine Effects
VI. Anisotropic Hyperfine Interaction
VII. g Anisotropy
VIII. Spin Relaxation
IX. Double-Resonance and Time-Domain ESR
X. Applications
XI. New Developments

GLOSSARY Spin density Fraction of unpaired electron spin probabil-
ity at a given nucleus in a molecular system.
Dot product Mathematical multiplication operation for Spin Hamiltonian Mathematical operator that operates
two vectors. oractsonspinwavefunctionsofaparamagneticsystem
ENDOR Abbreviation for the double-resonance tech- to give the energy levels of the system.
nique of electron nuclear double resonance. Wave function State function that can be used to calcu-
ESE Abbreviation for the time-domain electron spin res- late any property, typically energy levels, of a natural
onance technique of electron spin-echo spectroscopy. system, typically a molecule.
g Factor Constant characterizing the magnitude of the Waveguide Rectangular pipe of appropriate dimensions
spin angular momentum of an electron or a nucleus. to propagate microwaves in a given frequency range.
Hyperfine coupling Interaction energy or coupling be- Zeeman interaction Interaction energy of a magnetic
tween electron and nuclear spins. field with the spin angular momentum of a particle.
Perturbation theory Mathematical approximation me-
thod used to simplify the calculation of energy levels
from a Hamiltonian operator acting on a wave function ELECTRON SPIN RESONANCE is a type of magnetic
for a system. resonance spectroscopy dealing with transitions between

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