Effect of alkaline earth modifier ion on the optical, magnetic and electrical properties of lithium nickel borate glasses

Lithium nickel borate glasses were prepared by varying the modifier oxide from MgO to BaO by using the melt quenching technique. Characterization of the samples was carried out using FTIR, optical absorption and thermoluminescence (TL) techniques. The optical absorption studies point out that the octahedral positions of Ni2+ ions seem to be dominant when the glass matrix contains barium oxide as the modifier. The glass sample containing BaO as the modifier possesses a higher concentration of laser emitting octahedral Ni2+ ions (T-3(2g) -> (3)A(2g)) than the other modifier ions studied. Electrical measurements were carried out by impedance spectroscopy as a function of frequency and temperature over the frequency range of 10 Hz to 10(6) Hz and at a temperature range from 303 K to 523 K. Ion relaxation behavior of lithium nickel borate glasses was studied using the electric modulus formalism. (C) 2008 Elsevier B.V. All rights reserved.