This document discusses blue phosphor made from cerium-doped strontium barium niobate (SBN) nanoparticles. SBN has a tetragonal tungsten bronze structure and can be prepared using a sol-gel method for its advantages of low temperature processing, homogenity, and better structure control. The document characterizes the cerium-doped SBN using XRD, IR, absorption spectroscopy, and emission spectroscopy. It concludes that cerium doping produces a blue emitter while maintaining the SBN structure and changing its optical properties.

2. BLUE PHOSPHOR
NANO SIZE
 APPLICATIONS
AIM

3. APPLICATIONS
Holographic information recording.
Used as blue phosphor for lighting .
Display devices
Led

4. STRONTIUM BARIUM NIOBATE
SBN chemical formula
SrxBa(1-x)Nb2O6 , x=0.5
Structure of sbnTetragonal
TungstenBronze structure
Ferroelectrc material
Its structural formula is
(A1)4(A2)2C4(B1)2(B2)8O30
A1-pentagonol,A2-tetragonal,
C-trigonal

5. PREPARATION OF SBN
 Sol-gel method
 Advantages
Low temperature
Homogenity
Better control of structure

6. EXPERIMENTAL METHOD
Sr-EDTA solution
Barium nitrate
Citric acid (molar ratio of CA:Nb=3:1)
Nb-citrate solution
NH3.nH2O (pH=8)
EDTA aqueous solution EDTA aqueous solution Citric acid aqueous solution
Ba-EDTA solution
Precursor solution
Drying at 800C
Precursor gel
Heat treatment at 8000C
Strontium nitrate Nb2O5.nH2O

7. CHARACTERISATION
OF CERIUM DOPED SBN
XRD
IR

8. XRD
The Debye-Scherrer Method
Equation to find Crystallite
Size
t= 0.9*λ / βcosθ

9. IR
FTIR spectroscopy is a technique that provides information about
the chemical bonding or molecular structure of materials .
 The absorption peak associated with Sr-O, Ba-O and Nb-O between
500 and 850 cm-1 are prominent.

10. ABSORPTION SPECTRUM OF
CERIUM DOPED SBN
ABSORPTION SPECTRUM
 In order to measure the amount
of light absorbed by the sample
at room temperature, the
samples were excited from 200
nm to 700 nm wavelengths at
room temperature

11. (αhν)1/2 = A[hν- Eg]
Band gap of cerium doped
SBN=3.2ev

12. EMISSION SPECTRUM
Electronic configuration
of cerium (Z = 58)
4f25d06s2

13. CONCLUSION
BLUE EMITTER IS MADE
STRUCTURE OF SBN UNCHANGED
OPTICAL PROPERTY CHANGES

14. Thank you