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Rare-earth Sulfide Pigment by Solution Combustion
Method
Arun M Umarji, G. P. Shivakumara, Basavaraj
Angadi and K. C. Patil, Materials Research
Centre Indian Institute of Science, Bangalore
560012 INDIA   umarji_at_mrc.iisc.ernet.in
NMITLI Project funded by CSIR, New Delhi
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Ultrasonic nebulised spray pyrolysis of an
aqueous combustion mixture for the deposition of
ZnO thin films for gas sensing Ujwala Ail, S.A.
Shivashankar and A.M. Umarji
Thanks to Dr K C Adiga for discussions and support
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Combustion synthesis and color evolution studies
of Praseodymium doped Ceria Environmentally
safe red pigmentsBasavaraj Angadi1,3, K. C.
Patil2, A. M. Umarji3
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High Temperature electrical and Magnetic studies
on Na0.76 Co(1-X)/Nix/FexO2 Prepared by
aqueous combustion method Venkatesan.P1
N.Y.Vasanthacharya2 V.B.Shenoy1, A.M.Umarji1
Na0.74Co1-xFexO2 prepared by combustion synthesis
followed by hot pressing High Density gt98
theoretical Maximum temperature lt 850C
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Fabrication of inert/CS2 atmosphere combustion
chamber
Schematic diagram
Top view port
Emergency pressure releaser
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Water cooling
Al-bell jar
Side view port
Furnace
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Al-Supports
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Al-Block
Electrical feedthroughs
Gas inlet
Gas outlet/ to pump
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Fabrication of inert/CS2 atmosphere combustion
chamber
Photograph
Quartz setup
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Preheated furnace mounted on the tripod on the
base plate
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Quartz setup kept inside the furnace and
connected to the gas inlet
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Success on Ce2S3/Ce4O4S3 and La2O2S

• Formation of Ce2S3/La2O2S by inert/CS2
  atmosphere combustion reaction
• Using Cerium/Lanthanum nitrate and Thiourea
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  Ce(NO3)3 5 N2H4CS 2 La(NO3)3 5 N2H4CS
• Preheated furnace at 500 600 C
• Avoid oxygen by partially evacuating the chamber
  and refilling by inert gas
• Create excess sulphur partial pressure by CS2
  flow inside the specially designed quartz setup
  kept inside the belljar
• Cool to RT in CS2/N2 flow

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Results of ?-Ce2S3
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Results of ?-Ce2S3
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Results of ?-Ce2S3
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Results of ?-Ce2S3
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Results of ?-La2S3
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Rare earth sulphides Synthesis using
Ammoniumthocyanate
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Experimental set up Fabrication of tubular
furnace for combustion in N2/H2S Atmosphere
Sulfudisation of CeCl36H2O and RE2O3 by using
ammonium thiocyanate instead of
thiourea. Cerium Chemical reactions 2 CeCl3
6H2O8NH4SCN Ce2S310 H2O
8 CO2 8 N2NH4Cl 2CeCl36H2O8NH2CSNH2
Ce2S310 H2O 8 CO2 8 N2NH4Cl
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Direct Synthesis of Ce2O2S/Ce4O4S3 and La2O2S

• Formation of Ce2O2S/La2O2S in an inert/H2S
  atmosphere by combustion reaction
• Using Cerium Chloride/Lanthanum sesqui oxide and
  ammonium thiocyanate
  3CeCl36H2O 8NH4CSN 3 La2O3
  8 NH4CSN
• Preheated furnace at 350 400 C
• Avoid oxygen by purging N2 gas initially into
  the chamber
• Create excess sulphur partial pressure by H2S/N2
  flow inside the specially designed tubular
  furnace
• Cool to RT in H2S/N2 flow

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Photographs of Pigment Powders Produced by
direct Sulfudisation of Rare Earth Oxides and
Salts
Sample1
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Color analysis of rare earth sulfides/oxysulfides
Fig.6. The variation of diffuse reflectance
spectra for Cerium,Lanthanum,Neodymium,
Praseodymium sulphides (by using Ammonium
thiocyanate and N2-H2S.)
 
Table 3 The corresponding L a b
parameters of the above graphs are as follows
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Effect of use of with CeCl3.6H2O and CeO2
Sample1- Ce(NO3)3.6H2OGlycineCeCl36H2O
Sample2-(NH4)2Ce(NO3)6GlycineCeCl36H2O Samp
le3-(NH4)2Ce(NO3)6AmmAcetateCeCl36H2O
Sample4-Ce(NO3)36H2OAmmAcetateCeCl36H2O
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XRD pattern of Ceria obtained form Ce(NO3)4
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Table 1 A)X-ray analysis and B)Colour analysis
of ceria obtained by different fuels and
different precursors with added CeCl3
A)
B)
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Sulfudised product in IIT Madras-
XRD Pattern
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?-Ce2S3
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?-Ce2S3 Flurinated
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Ce 2.5 Na 0.5S4
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??-Ce2S3-Fluorinated
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Sample-3-Na-2
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CONCLUSION

• Solution combustion technique can be used to
  make sulfide/oxy-sulfide inorganic materials
• Nano CeO2 made by solution combustion method is
  good precursor for making gama Ce3S4

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Thank You
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Results of Cerium

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Combustion Synthesis of Ce Chloride/oxychloride 1.
Synthesis of ceria by solution combustion method
using different precursors and different fuels
with CeCl36H2O 2.Cerum nitrate, Ceric ammonium
nitrate precursors Glycine and ammonium acetate
-- fuels. 3.Addition of CeCl3 lead to the
decrease in crystallite size and color. Chemical
reaction 1) 3 Ce(NO3)3 6H2O 5 C2H5NO2
3CeCl36H2O 6CeO2 12H2O10CO2
7N2HCl 2) (NH4)2Ce(NO3)6 NH4OOCCH3
CeCl36H2O CeO2CO2H2ONH4ClN2
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SEM images of Ce2O2S/Ce2S3
Thermo gravimetrc analysis of cerium
sulfide/oxysulfide.
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Results of Lanthanum
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SEM images of La2O2S
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Results of Neodymium
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SEM Images of Nd2O2S
Thermogravimetric analysis Neodymium oxysulfides
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Results of Pr2O2S/Pr2S3
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SEM images of Pr2S3/Pr2O2S
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• Future plan/direction
• Standardise the preparation of Ce oxychloride
  for sulfudisation in IIT Madras
• Thermal decomposition of rare earth sulphates
  which can lead to the formation of corresponding
  sulfides or oxysulfides
• Using of cerium phosphate as a precursor for
  sulfides and oxy sulfides
• Efforts will be made to scale up the
  preparation of cerium sulphide, lanthanum
  sulphide or the oxysulphides by the inert H2S
  atmosphere combustion reactions.
• Using of trapping agent in the combustion
  synthesis to trap residual species present, such
  as oxygen chlorine etc.

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Sulfudisation of CeCl36H2O and RE2O3 by using
ammonium thiocyanate instead of
thiourea. Cerium Chemical reactions 2 CeCl3
6H2O8NH4SCN Ce2O2S/Ce2S310 H2O
8 CO2 8 N2NH4Cl 2CeCl36H2O8NH2CSNH2
Ce2O2S/Ce2S310 H2O 8 CO2 8
N2NH4Cl Lanthanum Chemical reaction 2 Ln2O38
NH4SCN Ln2S2O/La2S3 10 H2O 8
CO2 8 N2 2 Ln2O38NH2CSNH2
Ln2S2O/La2S3 10 H2O 8 CO2 8 N2 Ln La, Nd,
Pr