The optical properties of transparent chromium-doped glass-ceramics with the chemical composition similar to that of cunyite
(Cr 4+ :Ca 2 GeO 4 ) crystal were investigated. Room temperature absorption, DTA, XRD as well as fluorescence were measured. Parent (as quenched)
glass does not exhibit any fluorescence; after the heat treatment Cr 4+ fluorescence band appears at 1280 nm, very similar to the emission of
Cr 4+ :Ca 2 GeO 4 bulk crystals. Optical properties of nanocrystals formed in the glass-ceramics. The size of crystallites is below 600nm.
glass-ceramics we concluded that the nanocrystal phase is a modified Ca 2 GeO 4 structure.
In order to increase the fluorescence and synthesis more small crystals, we doped TiO 2 and ZrO 2 as nucleating agents, glass does not
exhibit any fluorescence when glass-ceramics does not heat treatment ; after the heat treatment Cr 4+ fluorescence band appears at 1280 nm too.
The crystals formed in glass media after heat-treatment have spherulitic shape with the size up to 300-500nm, and there are more nanocrystals
distribute the surface, especially doped TiO 2 we found the more smaller crystals in it.
We expect that crystallites with the size below 100 nm may be formed by adjustment of initial glass composition with nucleating agents and optimization of heat-treatment procedure parameters.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0730110-170742 |
| Date | 30 July 2010 |
| Creators | Huang, Chih-wei |
| Contributors | Wood-Hi Cheng, Jau-Sheng Wang, Chin-Ping Yu |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0730110-170742 |
| Rights | not_available, Copyright information available at source archive |
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