Samples of B2O3-Li2O glass were exposed to 60Co γ-irradiation and measured with 4-pulse 1-dimensional electron spin echo envelop modulation spectroscopy and hyperfine sub-level correlation spectroscopy. Four-pulse 1-dimensional electron spin echo envelop modulation revealed the values of χzz ≤ 0.7MHz, η ~ 0.4 Taniso ≤ 0.8MHz, and Aiso ~ 0.6MHz for the second B neighbor. In a- and c-B2O3, 4-pulse 1-dimensional electron spin echo envelop modulation uncovered the value of χzz ~ 2.6MHz for the second B neighbor. Hyperfine sub-level correlation spectroscopy in the B2O3-Li2O glass revealed a weak coupling with χzz ≤ 0.7MHz, η ~ 0.37, Taniso ≤ 0.9MHz, and Aiso ≤ 0.9MHz due to the interaction of the spin with the second B neighbor loosely bonded with the defect. An orthoborate group in the proximity of fourfold coordinated B cluster reproduces the experimental parameters most satisfactorily.

Equivalent Exploitation of Four-Pulse One-Dimensional ESEEM and HYSCORE Spectroscopies for the Elucidation of BOHC Defects in Borate Glasses Supported by Quantum Mechanical Calculations. G.Kordas: Physical Review B, 2003, 68[2], 024202 (11pp)