On the structure of trapped holes in borosilicates

Citation
Ia. Shkrob et Vf. Tarasov, On the structure of trapped holes in borosilicates, J CHEM PHYS, 113(23), 2000, pp. 10723-10732
Citations number
31
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF CHEMICAL PHYSICS
ISSN journal
00219606 → ACNP
Volume
113
Issue
23
Year of publication
2000
Pages
10723 - 10732
Database
ISI
SICI code
0021-9606(200012)113:23<10723:OTSOTH>2.0.ZU;2-D
Abstract
Danburite (CaB2Si2O8) is a naturally occurring borosilicate mineral that is a crystalline analog of borosilicate glass. Using two-dimensional correlat ion electron spin echo envelope modulation spectroscopy, we determined the structure of the prevalent radiation-induced defect, boron oxygen hole cent er, in this mineral. The hole is trapped by nonbridging oxygen in a strongl y distorted -O3B-O--BO3- linkage; the precursor of the hole center is a Ca2 + vacancy. These results and computer modeling suggest that in borosilicate glasses, the hole center is the same >B-O-. radical as in alkali borate gl asses. We suggest that a >B-O- unit near a cation vacancy is the precursor of hole centers in both types of glasses. (C) 2000 American Institute of Ph ysics. [S0021-9606(00)71347-X].