Paramagnetische Elektronenresonanz thermisch und durch Strahlung erzeugter Zentren in Bornitrid

Abstract

By X-rays, ultraviolet, and γ-radiation or by heating to more than 1850 °C in powdered or sintered boronnitride centres are produced, which give an EPR-spectrum with 10 lines a=7.8 ± 0.1 Gauss apart with g=2.0027 ± 0.0003 for BN of natural isotopic composition (81.17% 11B; 18.83% 10B), and a single line for 10BN enriched to 91% 10B. The spectra are analysed as built up from 4 systems of spectra, caused by surroundings of 3 boron atoms, 3, 2, 1, or 0 of which are 11B, each occuring with the proper probability. The intensity of the different systems was calculated by assuming GAussian line shape and equal | ψ (0) |2 and line width for 11B and 10B. It is possible, that the EPR is caused by impurity atoms on the places of N or in the centre of B3N3-rings. Other spectra caused in BN by X-rays or by neutrons in a pile are discussed elsewhere 3, 8.