Accession Number:

ADA155210

Title:

Magnetic Effects in Non-Crystalline Semiconductors.

Descriptive Note:

Interim rept.,

Corporate Author:

UTAH UNIV SALT LAKE CITY DEPT OF PHYSICS

Personal Author(s):

Report Date:

1983-01-01

Pagination or Media Count:

98.0

Abstract:

Most amorphous semiconductors are essentially diamagnetic, but a paramagnetic contribution to the magnetic susceptibility is present in some materials due to either the presence of inadvertent paramagnetic impurities or the existence of paramagnetic defects such as unsatisfied or dangling bonds. When light of energy near the band gap energy is applied to these semiconductors there is an optically-induced paramagnetism which results. In most cases this optically-induced paramagnetism is metastable at low enough temperatures. Although the exact cause of the paramagnetism depends on the specific amorphous semiconductor, two general mechanisms have been identified the optical rearrangement of charge in existing defects or the optically-induced creation of new defects. In either of these cases the optically-induced paramagnetism can be annealed, in some cases optically and in all cases by heating well below the glass transition or crystallization temperatures. Magnetic effects can be used effectively to probe local structural order of defects, impurities or major constituent atoms. Some magnetic processes are also useful in probing low energy excitations in amorphous semiconductors. The primary techniques are electron spin resonance, nuclear magnetic resnonace, nuclear quadrupole resonance and Mossbauer spectroscopy.

Subject Categories:

  • Electricity and Magnetism
  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE