Paramagnetic states induced in amorphous As, Se, andAs2Se3by electron bombardment at 77 K

Amorphous As, Se, and ${\mathrm{As}}_2$ ${\mathrm{Se}}_3$ exhibit electron spin resonance (ESR) responses after irradiation with high energy (2 MeV) electrons at 77 K. Some of these ESR responses are stable at temperatures below about 77 K, although all are unstable at 300 K. In As and ${\mathrm{As}}_2$ ${\mathrm{Se}}_3$ the electron irradiation produces ESR responses similar to, but distinguishable from, those created by irradiation with low intensity (∼ 1 mW ${\mathrm{cm}}^{-2\mathrm{}}$) near infrared light of near-band-gap energies (optically induced states). Qualitative features of the ESR line shapes suggest that some of the paramagnetic states produced by electron irradiation are either less distorted or more highly localized than those which can be induced optically. The paramagnetic states produced by electron irradiation are most likely the result of atomic displacements.