X-ray absorption fine structure of samarium-doped borate glasses

Abstract
Samarium LIII x-ray absorption fine structure spectra for both Sm2+ and Sm3+-doped (100-X)B2O3 XNa2O (X=10,15,20) glasses and both Sm2+ and Sm3+-doped 85B2O3 (15-X)Al2O3 XNa2O (X=5,10) glasses were measured using synchrotron radiation. The oxygen coordination number of samarium in Sm2+-doped glass is different from that of the Sm3+-doped glass with the same composition while the nearest neighbor Sm–O distances are closely the same. The change of coordination numbers with alkali or aluminum addition was related to the variation of the optical hole width of Sm2+-doped glasses.