FT-EPR spectroscopy in the borate system

Abstract 80-mol% B2O3 20-mol% Li2O glass has been subjected to γ-irradiation at room temperature and subsequently studied by CW EPR (continuous wave electron paramagnetic resonance), ECHO-fs (field sweep), 4p-ESEEM (electron spin echo envelop modulation spectroscopy), 2D-HYSCORE (hyperfine sublevel correlation) spectroscopy and pulse ENDOR (electron nuclear double resonance) spectroscopies. The variation of the EPR signal with the conditions of measurements suggests that several centers contribute to the signal. The Aiso-couplings of the next neighbor have been determined by these methods. One may suggest on this ground the existence of the tetraborate, diborate and boron network non-bridging oxygen (BN-nbo) structures, though this preliminary effort needs supplementary investigational work to be convinced about it.