Preparation of the Bi12SiO20 thin films by the solgel method

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Preparation of the Bi12SiO20 thin films by the
sol-gel method

• . Kunej, A. Veber and D. Suvorov
• Advanced Materials
• Joef Stefan Institute

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Outline

• Introduction
• Aim of work
• Experimental
• Results
• Sapphire
• Si/SiO2/TiO2/Pt
• Spinel MgAl2O4
• Conclusions

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Introduction
SILLENITE
M. Valant, D. Suvorov J. Am. Ceram. Soc.,
8412, 2900-904, 2001
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Aim of work

• Preparing Bi12SiO20 (BSO) thin films using
  sol-gel method
• Determining microstructure and thickness of BSO
  thin films deposited on substrates
• Sapphire
• Si/SiO2/TiO2/Pt
• Spinel MgAl2O4

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Experimental SOL-GEL Synthesis
Bi(NO3)35H2O
Vacuum drying 60C/96h

• Used chemicals
• Bismuth (III) nitrate
• Bi(NO3)35H2O
• Tetraethly orthosilicate
• (TEOS) Si(OC2H5)5
• Acetic acid
• CH3COOH
• Ethanolamine
• H2NCH2CH2OH
• 2-ethoxyethanol
• C2H5OCH2CH2OH

Acetic acid Ethanolamine
Bi(NO3)
Bismuth complex solution
Sol
Spin-coating (5000 rpm)
4x
Analytical methods XRD ? SEM ? AFM
Firing 300-700C/1h
Pyrolysis 220C/2min
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Results
Influence of solvent on gelation time
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Results Sapphire
Results Sapphire
Spin-coating 4 x 5000 rpm Firing 700C/1h
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Results Sapphire
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Results Si/SiO2/TiO2/Pt
Spin-coating 4 x 5000 rpm Firing 700C/1h
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Results Si/SiO2/TiO2/Pt
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Results Spinel
Spin-coating 4 x 5000 rpm Firing 700C/1h
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Results Spinel
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Conclusions

• The Bi12SiO20 (BSO) thin films were successfully
  prepared by the sol-gel method
• The BSO thin film obtained on sapphire substrate
  is porous with rough surface
• Homogeneous BSO thin film of thickness ? 230nm
  was obtained for the thin film deposited on
  Si/SiO2/TiO2/Pt substrate
• Thin film deposited on the spinel substrate shows
  homogeneous microstructure with grain size of
  200-500nm.
• Future work
• Optimization of BSO sol-gel precursor
• Obtaining denser BSO thin films
• Dielectric measurements of BSO thin films

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Thank you for your attention!