B-11 NMR investigations in xV(2)O(5)-B2O3 and xV(2)O(5)-B2O3-PbO glasses

11B (I = 3/2) MAS NMR in the binary glass system xV(2)O(5)-B2O3 (x = 0.053, 0.43) and the ternary glass system xV(2)O(5)-B2O3-PbO (0.1 less than or eq ual to x less than or equal to 1.5) has been investigated at room temperatu re. In the xV(2)O(5)-B2O3 glasses, one NMR line due to BO3 unit was observe d. Meanwhile in the xV(2)O(5)-B2O3-PbO, two NMR lines which arise from BO3 and BO4 units were detected, where the appearance of BO4 units is produced by the presence of PbO. From the computer-simulation of the B-11 NMR centra l transition line (m = -1/2 <-> 1/2), the quadrupole parameters (e(2)qQ/h a nd eta) for BO3 units in xV(2)O(5)-B2O3, and those for BO3 and BO4 units in xV(2)O(5)-B2O3-PbO were obtained as a function of x. As the V2O5 content i ncreases in xV(2)O(5)-B2O3-PbO, the e(2)qQ/h and eta values of the BO3- ass ociated resonance are found to slightly decrease and increase, respectively . Meanwhile, the e(2)qQ/h and eta values of BO4- associated resonance in xV (2)O(5)-B2O3-PbO are found to slightly increase and decrease, respectively. By comparing the intensities of the total transitions (m = -3/2 <->, -1/2, m = -1/2 <-> 1/2, and 1/2 <-> 3/2) for the B-11 NMR line of BO3 and BO4 un its contained in xV(2)O(5)-B2O3-PbO with those of respective standard sampl es of 0.053V(2)O(5)-B2O3 and NaBH4, the quantitative fractions of BO3 and B O4 in xV(2)O(5)-B2O3-PbO were obtained as a function of x. (C) 2000 Elsevie r Science B.V. All rights reserved.