The Microwave Absorption Properties of La0.67Ba0.33Mn0.98TM0.02O3 (TM=Ti and Ni)
The Microwave Absorption Properties of La0.67Ba0.33Mn0.98TM0.02O3
(TM=Ti and Ni)
Sitti Ahmiatri Saptari1, a, Azwar Manaf2,b and Budhy Kurniawan2,c
1
Faculty of Science and Technology, State Islamic University, Jakarta, Indonesia
2
Departement of Physics, University of Indonesia, Depok, Indonesia
a
[email protected], [email protected], [email protected]
Keywords: microwave absorption; La0.67Ba0.33Mn0.98Ti0.02O3; La0.67Ba0.03Mn0.98Ni0.02O3
Abstract. The doped lanthanum manganites has unusual magnetic and transport properties, which
makes it possible for this material to be used for absorbing microwave. In this study,
La0.67Ba0.33Mn0.98TM0.02O3 (TM = Ti and Ni) were prepared by solid state reaction method as
microwave absorption material. The crystal structure and magnetic properties were characterized
by XRD and permagraph. Refinement results showed both of samples are single phase with
monoclinic crystal structure. And hysteresis loops results showed that the
La0.67Ba0.33Mn0.98TM0.02O3 (TM = Ti and Ni) samples are soft magnetic materials. Microwave
absorption properties were investigated in the frequency range 8-12 GHz using vector network
analyzer. An optimal reflection loss of -13 dB is reached at 11.5 GHz for TM = Ti and optimal
reflection loss of -6 dB is reached at 11.5 GHz for TM = Ni.
.
Introduction
Microwave in the range 1 -20 GHz are increasingly used in the field of wireless communication,
local area network, and so on. However, the electromagnetic interference (EMI) limits their
applications and hence much attention has been paid to find suitable microwave absorption
materials. conventional spinel-type ferrites do not function well in the GHz range due to a drop in
the complex permeability µ r as given by Snoek’s limit [1]. In recent years, the doped rare earthtransition metal oxides, especially doped LaMnO3, with their colossal magneto-resistance (CMR)
effect, have shown high potential applications in the field of magnetic electronics functional
materials. Besides the CMR effect, the particular electronic structure and unusual electromagnetic
characteristics of the oxide indicate that it has high applications as microwave absorption materials
[2-5].
In this paper, with the aim finding a material suitable for use as a microwave absorber in GHz
band range, La0.67Ba0.33Mn0.98TM0.02O3 (TM = Ti and Ni) powders were prepared by the solid state
reaction method. We investigate the microwave absorption properties of soft magnetic
La0.67Ba0.33Mn0.98TM0.02O3 (TM = Ti and Ni). Our experimental results demonstrate that
La0.67Ba0.33Mn0.98TM0.02O3 (TM = Ti and Ni) are promising for the application produce broadband
and effective microwave absorbers.
Experimental
La0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni) ceramic samples were synthesized following the
solid-state reaction route by mixing La2O3, MnCO3, BaCO3, TiO2 and NiO (Sigma Aldrich 99.99%
purity)
in their
stoichiometric ratios, with Planetary Ball Milling during 25 hours.
Thermogravimetric analyzer (TGA) was used to determine the crystallization temperature. The
calcinations performed at 800oC for 10 h. The calcined powders were then pressed into pellets and
finally sintered at 1200oC for 2 h.
The crystal structure of the samples were determined by X-ray diffraction (XRD) using CuKα
radiation (λ = 1.54 Å) operated at 35 kV and 25 mA. The magnetic properties of the samples were
observed by permagraph. The reflection loss (RL) of the samples were measured between 8 and 12
GHz using vector network analyzer.
Result and Discussion
Fig. 1 presents the XRD patterns of the La 0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni) samples.
The diffraction patterns of all the samples show single phase and free from impurities. Crystal
structure was further refined by GSAS software, refinement results of the
La0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni) samples can be seen in Table 1. The refinement results
provide information that La0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni) samples have formed a single
phase with monoclinic crystal structure and space group I 1 2/c 1.
Intensity
La0.67Ba0.33Mn0.98Ni0.02O3
Intensity
La0.67Ba0.33Mn0.98Ti0.02O3
0
10
20
30
40
50
60
70
80
90
2 theta
Fig. 1. XRD pattern of La0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni) samples
Table 1. Refinement results of La0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni) samples
Sample
a (Å)
b(Å)
c(Å)
β
χ2
Densitas (g/cm3)
Ti
Ni
5.53
5.53
5.54
5.52
7.83
7.82
89.95
89.92
1.19
1.25
6.68
6.72
To study the magnetic properties of the samples, the magnetic hysteresis loops of the samples at
room temperature were measured. It is shown that the samples are ferromagnetic behaviors at
room temperature. Fig. 2 shows the image of magnetic hysteresis loops, it exhibits the soft
magnetic property of La0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni) samples. The values of
saturation magnetization (Ms) are 0.10 T and 0.15 T for La0.67Ba0.33Mn0.98Ti0.02O3 and
La0.67Ba0.33Mn0.98Ni0.02O3 respectively.
0.15
La0.67Ba0.33Mn0.98Ti0.02O3
La0.67Ba0.33Mn0.98Ni0.02O3
J (T)
0.10
0.05
0.00
-1500
-1000
-500
0
-0.05
500
1000
1500
H (kA/m)
-0.10
-0.15
Fig. 2. Hysteresis loops of La0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni) samples
0
-1
La0.67Ba0.33Mn0.98Ni0.02O3
Loss (dB)
-2
-3
-4
-5
-6
-7
0
-2
La0.67Ba0.33Mn0.98Ti0.02O3
Loss (dB)
-4
-6
-8
-10
-12
-14
7G
8G
9G
10G
11G
12G
13G
freq (Hz)
Fig. 3. Microwave absorption performance of La0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni)
Reflectivity is usually used as a parameter to characterized the microwave absorption
performance. The reflectivity of the single layer absorber could be expressed by the following
equation [6] :
Zin = (µ/ɛ)½ tanh (j2πfd(µɛ)½)
(1)
Z0 = (µ 0/ɛ0)½
(2)
R = 20 log10 │( Zin - Z0) / ( Zin + Z0 ) │
(3)
where Zin and Z0 are the impedances of the absorber and free space respectively, µ and ɛ the
permeability and permittivity of the absorber, µ 0 and ɛ0 the permeability and permittivity of free
space, d the absorber’s thickness.
Fig. 3 shows the reflection loss spectra of the La 0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni)
samples in the frequency range 8 – 12 GHz. It is clear that the position of reflection loss peak
maintain at ~ 11.5 GHz, the maximum values of reflection are -13 dB and -6 dB for
La0.67Ba0.33Mn0.98Ti0.02O3 and La0.67Ba0.33Mn0.98Ni0.02O3 respectively.
Conclusion
In summary, the transition metal doped La0.67Ba0.33Mn0.98TM0.02O3 (TM = Ti and Ni) powders
have been fabricated successfully by the conventional solid state reaction method. Experimental
results show that the position of reflection loss peak maintain at ~ 11.5 GHz, the maximum values
of reflection are -13 dB and -6 dB for La0.67Ba0.33Mn0.98Ti0.02O3 and La0.67Ba0.33Mn0.98Ni0.02O3
respectively.
References
[1]
[2]
[3]
[4]
[5]
[6]
K. S. Zhou, H. Xia, K. L. Huang, l. W. Deng, D. Wang, Y. P. Zhou, S. H. Ghou, The
microwave absoption properties of La0.8Sr0.2Mn1-yFeyO3 nanocrystalline powders in the
frequency range 2 – 18 GHz, Physica B 404 (2009) 175-179
Y. L. Cheng, J. M. Dai, D. J. Wu, Y. P. Sun, Electromagnetic and microwave absorption
properties of carbonyl iron/ La0.6Sr0.4MnO3 composites, J. Magnetism and Magnet Mat. 322
(2010) 97-101
G. Li, G. Hu, H. D. Zhou, X. G. Li, Attractive microwave absorbing properties of
La1-xSrxMnO3 manganite powder, J. Mat. Chem. Phys. 75 (2006) 101-104
K. S. Zhou, J. J. Deng, L. S. Yin, S. H. Mao, S. H. Gao, Microwave absorbing properties of
La0.8Ba0.2MnO3 nano particles, Trans. Nonferrous Met. Soc. China 17 (2007) 947-950
K. S. Zhou, D. Wang, K. L. Huang, L. S Yin, Y. P. Zhou, S. H. Gao, Characteristics of
permittivity and permeability spectra in range of 2-18 GHz microwave frequency for
La1-xSrxMn1-yByO3 ( B = Fe, Co, Ni)Trans. Nonferrous Met. Soc. China 17 (2007) 1294-1299
S. Zhang, Q. Chao, Electromagnetic and microwave absorption performance of some
transition metal doped La0.7Sr0.3Mn1-xTMxO3±δ (TM = Fe, Co or Ni), mat. Sci. and Eng. B
177(2012) 678-684
(TM=Ti and Ni)
Sitti Ahmiatri Saptari1, a, Azwar Manaf2,b and Budhy Kurniawan2,c
1
Faculty of Science and Technology, State Islamic University, Jakarta, Indonesia
2
Departement of Physics, University of Indonesia, Depok, Indonesia
a
[email protected], [email protected], [email protected]
Keywords: microwave absorption; La0.67Ba0.33Mn0.98Ti0.02O3; La0.67Ba0.03Mn0.98Ni0.02O3
Abstract. The doped lanthanum manganites has unusual magnetic and transport properties, which
makes it possible for this material to be used for absorbing microwave. In this study,
La0.67Ba0.33Mn0.98TM0.02O3 (TM = Ti and Ni) were prepared by solid state reaction method as
microwave absorption material. The crystal structure and magnetic properties were characterized
by XRD and permagraph. Refinement results showed both of samples are single phase with
monoclinic crystal structure. And hysteresis loops results showed that the
La0.67Ba0.33Mn0.98TM0.02O3 (TM = Ti and Ni) samples are soft magnetic materials. Microwave
absorption properties were investigated in the frequency range 8-12 GHz using vector network
analyzer. An optimal reflection loss of -13 dB is reached at 11.5 GHz for TM = Ti and optimal
reflection loss of -6 dB is reached at 11.5 GHz for TM = Ni.
.
Introduction
Microwave in the range 1 -20 GHz are increasingly used in the field of wireless communication,
local area network, and so on. However, the electromagnetic interference (EMI) limits their
applications and hence much attention has been paid to find suitable microwave absorption
materials. conventional spinel-type ferrites do not function well in the GHz range due to a drop in
the complex permeability µ r as given by Snoek’s limit [1]. In recent years, the doped rare earthtransition metal oxides, especially doped LaMnO3, with their colossal magneto-resistance (CMR)
effect, have shown high potential applications in the field of magnetic electronics functional
materials. Besides the CMR effect, the particular electronic structure and unusual electromagnetic
characteristics of the oxide indicate that it has high applications as microwave absorption materials
[2-5].
In this paper, with the aim finding a material suitable for use as a microwave absorber in GHz
band range, La0.67Ba0.33Mn0.98TM0.02O3 (TM = Ti and Ni) powders were prepared by the solid state
reaction method. We investigate the microwave absorption properties of soft magnetic
La0.67Ba0.33Mn0.98TM0.02O3 (TM = Ti and Ni). Our experimental results demonstrate that
La0.67Ba0.33Mn0.98TM0.02O3 (TM = Ti and Ni) are promising for the application produce broadband
and effective microwave absorbers.
Experimental
La0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni) ceramic samples were synthesized following the
solid-state reaction route by mixing La2O3, MnCO3, BaCO3, TiO2 and NiO (Sigma Aldrich 99.99%
purity)
in their
stoichiometric ratios, with Planetary Ball Milling during 25 hours.
Thermogravimetric analyzer (TGA) was used to determine the crystallization temperature. The
calcinations performed at 800oC for 10 h. The calcined powders were then pressed into pellets and
finally sintered at 1200oC for 2 h.
The crystal structure of the samples were determined by X-ray diffraction (XRD) using CuKα
radiation (λ = 1.54 Å) operated at 35 kV and 25 mA. The magnetic properties of the samples were
observed by permagraph. The reflection loss (RL) of the samples were measured between 8 and 12
GHz using vector network analyzer.
Result and Discussion
Fig. 1 presents the XRD patterns of the La 0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni) samples.
The diffraction patterns of all the samples show single phase and free from impurities. Crystal
structure was further refined by GSAS software, refinement results of the
La0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni) samples can be seen in Table 1. The refinement results
provide information that La0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni) samples have formed a single
phase with monoclinic crystal structure and space group I 1 2/c 1.
Intensity
La0.67Ba0.33Mn0.98Ni0.02O3
Intensity
La0.67Ba0.33Mn0.98Ti0.02O3
0
10
20
30
40
50
60
70
80
90
2 theta
Fig. 1. XRD pattern of La0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni) samples
Table 1. Refinement results of La0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni) samples
Sample
a (Å)
b(Å)
c(Å)
β
χ2
Densitas (g/cm3)
Ti
Ni
5.53
5.53
5.54
5.52
7.83
7.82
89.95
89.92
1.19
1.25
6.68
6.72
To study the magnetic properties of the samples, the magnetic hysteresis loops of the samples at
room temperature were measured. It is shown that the samples are ferromagnetic behaviors at
room temperature. Fig. 2 shows the image of magnetic hysteresis loops, it exhibits the soft
magnetic property of La0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni) samples. The values of
saturation magnetization (Ms) are 0.10 T and 0.15 T for La0.67Ba0.33Mn0.98Ti0.02O3 and
La0.67Ba0.33Mn0.98Ni0.02O3 respectively.
0.15
La0.67Ba0.33Mn0.98Ti0.02O3
La0.67Ba0.33Mn0.98Ni0.02O3
J (T)
0.10
0.05
0.00
-1500
-1000
-500
0
-0.05
500
1000
1500
H (kA/m)
-0.10
-0.15
Fig. 2. Hysteresis loops of La0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni) samples
0
-1
La0.67Ba0.33Mn0.98Ni0.02O3
Loss (dB)
-2
-3
-4
-5
-6
-7
0
-2
La0.67Ba0.33Mn0.98Ti0.02O3
Loss (dB)
-4
-6
-8
-10
-12
-14
7G
8G
9G
10G
11G
12G
13G
freq (Hz)
Fig. 3. Microwave absorption performance of La0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni)
Reflectivity is usually used as a parameter to characterized the microwave absorption
performance. The reflectivity of the single layer absorber could be expressed by the following
equation [6] :
Zin = (µ/ɛ)½ tanh (j2πfd(µɛ)½)
(1)
Z0 = (µ 0/ɛ0)½
(2)
R = 20 log10 │( Zin - Z0) / ( Zin + Z0 ) │
(3)
where Zin and Z0 are the impedances of the absorber and free space respectively, µ and ɛ the
permeability and permittivity of the absorber, µ 0 and ɛ0 the permeability and permittivity of free
space, d the absorber’s thickness.
Fig. 3 shows the reflection loss spectra of the La 0.67Ba0.33Mn0.98TM0.02O3 (TM= Ti and Ni)
samples in the frequency range 8 – 12 GHz. It is clear that the position of reflection loss peak
maintain at ~ 11.5 GHz, the maximum values of reflection are -13 dB and -6 dB for
La0.67Ba0.33Mn0.98Ti0.02O3 and La0.67Ba0.33Mn0.98Ni0.02O3 respectively.
Conclusion
In summary, the transition metal doped La0.67Ba0.33Mn0.98TM0.02O3 (TM = Ti and Ni) powders
have been fabricated successfully by the conventional solid state reaction method. Experimental
results show that the position of reflection loss peak maintain at ~ 11.5 GHz, the maximum values
of reflection are -13 dB and -6 dB for La0.67Ba0.33Mn0.98Ti0.02O3 and La0.67Ba0.33Mn0.98Ni0.02O3
respectively.
References
[1]
[2]
[3]
[4]
[5]
[6]
K. S. Zhou, H. Xia, K. L. Huang, l. W. Deng, D. Wang, Y. P. Zhou, S. H. Ghou, The
microwave absoption properties of La0.8Sr0.2Mn1-yFeyO3 nanocrystalline powders in the
frequency range 2 – 18 GHz, Physica B 404 (2009) 175-179
Y. L. Cheng, J. M. Dai, D. J. Wu, Y. P. Sun, Electromagnetic and microwave absorption
properties of carbonyl iron/ La0.6Sr0.4MnO3 composites, J. Magnetism and Magnet Mat. 322
(2010) 97-101
G. Li, G. Hu, H. D. Zhou, X. G. Li, Attractive microwave absorbing properties of
La1-xSrxMnO3 manganite powder, J. Mat. Chem. Phys. 75 (2006) 101-104
K. S. Zhou, J. J. Deng, L. S. Yin, S. H. Mao, S. H. Gao, Microwave absorbing properties of
La0.8Ba0.2MnO3 nano particles, Trans. Nonferrous Met. Soc. China 17 (2007) 947-950
K. S. Zhou, D. Wang, K. L. Huang, L. S Yin, Y. P. Zhou, S. H. Gao, Characteristics of
permittivity and permeability spectra in range of 2-18 GHz microwave frequency for
La1-xSrxMn1-yByO3 ( B = Fe, Co, Ni)Trans. Nonferrous Met. Soc. China 17 (2007) 1294-1299
S. Zhang, Q. Chao, Electromagnetic and microwave absorption performance of some
transition metal doped La0.7Sr0.3Mn1-xTMxO3±δ (TM = Fe, Co or Ni), mat. Sci. and Eng. B
177(2012) 678-684