The Library
A multinuclear solid state NMR study of the sol-gel formation of amorphous Nb2O5-SiO2 materials
Tools
Tools
Tools
UNSPECIFIED (2005) A multinuclear solid state NMR study of the sol-gel formation of amorphous Nb2O5-SiO2 materials. SOLID STATE NUCLEAR MAGNETIC RESONANCE, 27 (1-2). pp. 28-36. doi:10.1016/j.ssnmr.2004.08.008 ISSN 0926-2040.
Research output not available from this repository.
Request-a-Copy directly from author or use local Library Get it For Me service.
Official URL: http://dx.doi.org/10.1016/j.ssnmr.2004.08.008
Abstract
Multinuclear H-1, C-13, O-17, Si-29 MAS and Nb-93 static NMR is reported from a series of sol-gel prepared (Nb2O5)(x)(SiO2)(1-x) materials with x = 0.03, 0.075 or 0.30. C-13 NM R shows that by 500 degreesC the organic precursor fragments have been removed although some residual carbon remains as a separate phase. The Si-29 NMR typically shows three Q-species (Q(2,3,4)) in the initial gels, and that with increasing heat treatment the average n of the Q(n)-species increases as the organic fragments and hydroxyl groups are removed. 170 shows unequivocally that the x = 0.03 and 0.075 samples are not phase separated, while at the much higher niobia-content of x = 0.30 Nb-O-Nb signals are readily detected, a definite indication of the atomic scale phase separation of Nb2O5. The x = 0.03 and 0.075 samples heated to 750degreesC are thus representative of amorphous niobium silicates. Comparison is made to other sol-gel prepared metal silicates especially with another Group Va metal tantalum. The effects of tantalum and niobium on the silica network are very different and it is suggested here that most of the niobium is present as NbO4, forming part of the silicate network. (C) 2004 Elsevier Inc. All rights reserved.
| Item Type: | Journal Article | ||||
|---|---|---|---|---|---|
| Subjects: | Q Science > QD Chemistry Q Science > QC Physics |
||||
| Journal or Publication Title: | SOLID STATE NUCLEAR MAGNETIC RESONANCE | ||||
| Publisher: | ACADEMIC PRESS INC ELSEVIER SCIENCE | ||||
| ISSN: | 0926-2040 | ||||
| Official Date: | January 2005 | ||||
| Dates: |
|
||||
| Volume: | 27 | ||||
| Number: | 1-2 | ||||
| Number of Pages: | 9 | ||||
| Page Range: | pp. 28-36 | ||||
| DOI: | 10.1016/j.ssnmr.2004.08.008 | ||||
| Publication Status: | Published |
Data sourced from Thomson Reuters' Web of Knowledge
Request changes or add full text files to a record
Repository staff actions (login required)
 |
View Item |
