A study was made of the electrical detection of cross relaxation processes in phosphorus-doped γ-irradiated silicon, where the dipolar-coupled electron spins of phosphorus and oxygen-vacancy complex (Si-SL1 center) underwent spin flip-flop transitions at specific magnetic field values for which the Zeeman splitting of the two centers became equal. Such cross relaxation signals were observed as a change in the sample photoconductivity at theoretically predicted magnetic fields without application of resonance frequency. This electrical detection of cross relaxation was a very simple and sensitive method for detecting paramagnetic centers in semiconductors.

Electrical Detection of Cross Relaxation between Electron Spins of Phosphorus and Oxygen-Vacancy Centers in Silicon. W.Akhtar, H.Morishita, K.Sawano, Y.Shiraki, L.S.Vlasenko, K.M.Itoh: Physical Review B, 2011, 84[4], 045204