Dependence of EPR Transition Probability on Magnetic Field

Abstract

Bleany’s theory of the g-value dependence of EPR transition probability is extended to a general case of rhombic ligand field by assuming that the system has a fictitious spin of 1/2. Given three principal g-values and a line shape function, changes in EPR spectra of polycrystalline aggregates with static magnetic field are calculated and a general equation of spectral curve are obtained. In the limiting case of a zero line width, the equation is reduced to an elliptic integral. This approach is applied to the simulation of the EPR spectra of normal and abnormal haemoglobins and pyrocatechase, and the theoretically and experimentally obtained spectra exhibit a good fit.