Electron Paramagnetic Resonance in Cu2O Compared with Other Semiconducting Properties

Electron paramagnetic resonance spectra have been observed in single crystals of Cu 2 O at 4.2 °K. Six samples cut from the same starting material were individually heated under a wide range of vacuum conditions and comparison was made between the observed e.p.r. spectrum and the luminescence, activation energy, and photoconductivity in the same sample. No direct relationships between e.p.r. spectra and the luminescence and photoconductivity were found although a good correlation between the complexity of the e.p.r. spectra and the room temperature activation energy was observed.