Intensity of forbidden hyperfine ( Delta m=2) transitions in the electron paramagnetic resonance spectra of transition ions

Abstract

Expmions are derived tor determining the angular variation in the intensity of the forbidden hyperfine transitions ( A M = 1, Am = i2) in the EPR spectra of Wansition ions. The intensities calculated using these expressions are mmpared with the predictions of Bleaney and Rubins and of Bir. It is found that third-order contributions arising from the nuclear spin operator as well as the quadmpole term are important in interpreting the intensity of forbidden hyperfine lines.