In recent times perovskite materials are extensively studied and have attracted much attention because they exhibit interesting the properties, showing potential applications in commercial, technical and biomedical. In Vietnam, perovskite materials be of interest research and applications are strong but with major research direction is to go deep into the electrical properties and the magnetic properties. The Lanthanum Strontium manganite is a perovskite-based crystal-structured ceramic material with the formula of La1-xSrxMnO3, where x describes the doping ratio. It has attracted much attention due to its good magnetic, electrical, and catalytic properties and is becoming an attractive possibility material in several biomedical applications, particularly with nano-size. In industry, this material is commonly used in as a cathode material in commercially produced solid oxide fuel cells. In this thesis, we present the Perovskite nanoparticles La1-xSrxMnO3 were successfully synthesized of the nanosize La1-xSrxMnO3 at x = 0; 0.1; 0.2; 0.3 and 0.4 which prepared by a modified sol-gel method. Structure and magnetic properties of them were systematically investigated in dependence on doped Sr ratio x. The structure was investigated by XRD and show slightly changed but magnetic properties varied strongly with changing the doping ratio x. Magnetic properties of samples were studied by Vibrating Sample Mode of Physical Properties Measurement System show at the room temperature, the samples show superparamagnetic properties with high saturated magnetization MS of 57 emu/g which strongly dependents on the doped Sr ratio x.

1. LOGO
Synthesis and Charaterization
of La1-xSrxMnO3 Perovskite
nanoparticles (x from 0 to 0.4)
Presenter : Tran Thi Mai – K55 IP
Supervisor: Dr. Nguyen Hoang Nam
Luu Manh Quynh

2. Content
 Introduction
 Experimental
 Results and discussion
 Conclusion

3. I. Introduction
1.1. The perovskite structure ABO3
perovskite has cubic structure and the cubic
unit cell has the network parameters is:
a = b = c ;
At the peak position of the cubic is the
cation A that around is the position of the
oxygen anion (located in the center of the
cubic face). The cation B is located in the
center cubic
The most important characteristic of the perovskite structure ABO3 is the
existence of the octahedral BO6
α = β = γ = 90o

4. I. Introduction
Crystal structure which can be changed from cubic to other formats such as
rhombohedral or orthorhombic when the ion A or ion B is changed by other
elements.
La1-xSrxMnO3 is a perovskite has the types
structure ABO3, in which the La ions are
replaced partially by Sr ions.
Due to structural differences have caused
lattice distortion and make the structure of
materials are changed from cubic to other
formats.

5. I. Introduction
2. Jahn – Teller distortion
When the doped or replacement, the ideal perovskite crystal structures will be
changed (occurs distortion)
Jahn – Teller effects occurs in a metal ions contained the odd number of the
electronic in the eg levels. However, this effect also occurs in compounds which
have the octahedral structure
Jahn – Teller distortion in the perovskite materials
When the octahedral structure change
will make to the length of association
changed according to the axis

6. I. Introduction
3. magnetic properties in the perovskite materials system La1-xAxMnO3
LaMnO3 compounds show antiferromagnetic properties due to the super-
exchange interaction (SE) between ions Mn3+. When doped ion alkanline metal
elements A2+ (Sr2+) into position of ions rare earth La3+, to ensure charge
neutralize conditions, the partial charge of ion Mn3+ transfer into ion Mn4+.
While the perovskite manganese not doped have dielectric anti –ferromagnetic
properties, the appearance of Mn4+ make the electrical conductivity increases
and appearance the ferromagnetic properties. When the doped concentration is
increased, the conductivity of the material also increases, up to a certain value,
the material will good conductivity as metal and to express strong ferromagnetic
properties

7. I. Introduction
5. The fabrication technology
The Solid phase reaction method (ceramic method)
The coprecipitation method
The hydrothermal method
The reaction Milling method
The sol – gel method

8. I. Introduction
The sol – gel method:
The process of creating materials by the sol - gel method consists of
4 main stages:
 Creating solution (sol)
 Gelled and shaped
 Drying
 Conglomeration
Các bước tạo vật liệu bằng phương pháp sol – gel
The main benefits of sol–gel processing are the high purity and uniform
nanostructure achievable at low temperatures.

9. II. Experimental
1. The instruments and chemicals
chemicals
Lanthanum oxide
(La2O3)
Strontium carbonate
(SrCO3)
Manganese nitrate
(Mn(NO3)2.4H2O)
Citric acid (CA.1H2O)
Nitric acid (HNO3)
instruments
Glass, pipet,
Thermometer
Magnetic stirrer (RH
basic KTC)
Drying furnace
(1350FX – 2E Model)
Calcining furnace
(CD 1600X CHIDA

10. II. Experimental
some image of instruments are used in the process
Magnetic stirrer
(RH basic KTC)
Drying furnace
(1350FX – 2E Model)
Calcining furnace
(CD 1600X CHIDA)

11. II. Experimental
CA
Sr(NO3)2 Mn(NO3)2
La(NO3)3
Stirring at 80oC
Sol gel compounds
xerogel
Fabrication process of material by sol – gel method
Drying Preheating Heating
at 1000o Cat 300o Cat 120o C
2. Fabrication process of material

12. II. Experimental
3. Some illustrative photos
a) b)
c)
Figure: a) sol is obtained after stirring at 80o C
b) and c) the product respectively obtained after
preheating at 300o C and heating at 1000o C

13. III. Results and discussion
10 20 30 40 50 60 70 80
0
100
200
300
400
500
x=0.4
Intensity(a.u)
2(degree)
(102)
(110) (104)
(202) (006)
(204)
(212)
(116)
(214) (300)
(220) (208)
XRD patterns of La0.6Sr0.4MnO3 nanoparticles.
1. Analysis of x-ray diffraction diagram (XRD)

14. III. Results and discussion
10 20 30 40 50 60 70 80
0
100
200
300
400
500
600
700
800
900
Intensity(a.u)
2(degree)
x=0
x=0.1
x=0.2
x=0.3
x=0.4
(102)
(110) (104)
(202)
(006)
(204)
(212)
(116)
(214) (300)
(220) (208)
XRD patterns of La1-xSrxMnO3 nanoparticles with x = 0, 0.1, 0.2, 0.3 and 0.4

15. III. Results and discussion
Table 1. The lattice parameters of the La1-xCaxMnO3 samples
with x from 0 to 0.4
Lattice parameters
Volume of cell
unit (Å3)
Sample a(Å) b(Å) c(Å)
x=0 5.48 5.49 7.71 231.96
x=0.1 5.54 5.45 7.92 239.13
x=0.2 5.49 5.50 7.76 234.31
x=0.3 5.49 5.48 7.82 235.26
x=0.4 5.47 5.46 7.91 236.24

16. III. Results and discussion
From XRD using the Debye – Scherrer formula:
Sample d(102) d(110) d(202) d(204)
d(212)
d(214)
x=0 29.6nm 17.5nm 30.9nm 28.4nm
13.0nm
22.5nm 23.7nm
x=0.1 28.2nm 17.9nm 25.7nm 28.7nm
14.7nm
21.3nm 22.7nm
x=0.2 26.7nm 19.3nm 19.5nm 25.5nm
17.4nm
14.5nm 20.5nm
x=0.3 24.7nm 19.4nm 18.4nm 24.6nm
16.5nm
14.1nm 19.6nm
x=0.4 27.0nm 22.7nm 19.0nm 25.0nm
15.8nm
15.4nm 20.8nm
The size of crystallites of La1-xSrxMnO3 with x from 0 to 0.4 as the table 2.
Table 2: Size of crystallites of La1-xSrxMnO3

17. III. Results and discussion
2. Analysis of Scanning electron micrographs (SEM), and
energy dispersive x – ray spectra (EDS)
SEM image and EDS spectra of the sample without doped (LaMnO3)

18. III. Results and discussion
SEM image and EDS spectra of the sample La0.9Sr0.1MnO3

19. III. Results and discussion
SEM image and EDS spectra of the sample La0.8Sr0.2MnO3

20. III. Results and discussion
SEM image and EDS spectra of the sample La0.7Sr0.3MnO3

21. III. Results and discussion
SEM image and EDS spectra of the sample La0.6Sr0.4MnO3

22. III. Results and discussion
a)
d)c)
b)
SEM images of La1-xSrxMnO3
with x = 0.1, 0.2, 0.3 and 0.4
annealed at 1000˚C for 2 h
shown in order from left to
right and top to bottom

23. IV. Conclusion
 In this thesis, we have successfully fabricated La1-xSrxMnO3
perovskite materials that nanoscale by the sol-gel method, doped
with Sr ratio from x = 0.1  0.4.
 The structure analysis shows that the structure of samples is
typical perovskite structure and the Sr was successfully doped into
sample. The structure of sample have small changes with changing
doping ratio x.

24. LOGO