Structural investigation of bismuth borate glass ceramics containing gadolinium ions by X-ray diffraction and FTIR spectroscopy

摘要

X-ray diffraction and FTIR spectroscopy measurements have been employed to investigate the xGd_2O_3 · (100 - x)[2Bi_2O_3 · B_2O_3] glass ceramics system, with 0 ≤ x ≤ 20 mol%. Heat treatment of glass samples at 625 ℃ for 24 h led to the formation of two crystalline phases. One crystalline phase is for the sample without gadolinium ions which belongs to the cubic system and another one is for the sample containing 20 mol% Gd_2O_3 which is orthorhombic with two unit cell parameters very close to each other. Between x = 0 mol% and x = 20 mol% there is a mixture of these crystalline phases. FTIR spectroscopy data suggest that the gadolinium ions play the network modifier role in the studied glasses. These data show that the glass structure consists of the BiO_3, BiO_6, BO_3, and BO_4 structural units, and the conversion among these units mainly depends on the Gd_2O_3 content.