Pyrolytic boron nitride (PBN) is a candidate material for armor elements of the discharge chamber in fusion reactors. Therefore it is urgent to study the origin of postradiation defects. In this paper the authors by combining the EPA and electron paramagnetic resonance (EPR) data deduce that the neutron irradiation of PBN results in the introduction of acceptor levels into the forbidden gap of the hexagonal boron nitride crystallites. And, that is the reason for decreasing concentration of positron sensitive defects (PSD) and Ps oxidation observed in anomalous magnetic quenching. When the annealing temperature is above or equal to 1300°/C the PSD concentration is observed to return to a higher value. These observations correlate with appearing TBC and indicate a redistribution of the defects in favor of those to which the filled donor levels correspond.
|Journal||Physica Status Solidi (A) Applied Research|
|Publication status||Published - Jul 1991|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics