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Synthesis and characterization of magnetite nanopowders
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Current Applied Physics 8 (2008) 758–760 www.elsevier.com/locate/cap www.kps.or.kr
Synthesis and characterization of magnetite nanopowders Ki-Chul Kim
a,d,1
, Eung-Kwon Kim b, Jae-Won Lee c, Sung-Lyul Maeng d, Young-Sung Kim c,*
a
d
BK 21, Physics Research Division, Institute of Basic Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea b School of Information and Communication Engineering, Sungkyunkwan University, Republic of Korea c Advanced Material Process of Information Technology, Sungkyunkwan University, Republic of Korea Cambridge-ETRI Joint R&D Centre, Electronics and Telecommunications Research Institute, Daejeon 305-350, Republic of Korea Received 27 July 2006; received in revised form 15 January 2007; accepted 27 April 2007 Available online 1 October 2007
Abstract We have synthesized the iron oxide nanoparticles using the newly developed mechanical ultrasonication method with the FeSO4 Æ 7H2O. We have also investigated the crystallographic structural properties, morphology, and magnetic properties of the nanopowders. According to the high resolution X-ray diffraction result, the as-synthesized iron oxide nanoparticles were magnetite (Fe3O4). The particle size of the magnetite nanoparticles was about 6 nm confirmed by transmission electron microscopy image. The particle shape was almost a sphere confirmed by scanning electron microscopy image. The coercivity and saturation magnetization of the as-synthesized iron oxide nanopowders were 114 Oe, and 3.7 emu/g, respectively. Ó 2007 Elsevier B.V. All rights reserved. PACS: 61.46.Df; 75.75.+a; 87.80.Ek Keywords: Synthesis of magnetic nanoparticles; Magnetite; Iron oxide; Mechanical ultrasonication method
1. Introduction The synthesis of the iron oxide particles has been a field intense study due to the novel properties and potentiality on the practical applications to ferrofluids, rotary shaft sealing, oscillation damping and position sensing [1–3]. The sub10 nm iron oxide nanoparticles exhibit superparamagnetic behavior, because each particle can be considered as a single magnetic domain. Superparamagnetic nanoparticles offer a high potentiality for biomedical applications, such as medical diagnosis with contrast enhancement of magnetic resonance imaging (MRI) [4], AC magnetic field-assisted cancer therapy, magnetic cell separation [5], and magnetically controlled transport of anti-cancer drugs [6]. *
Corresponding author. Tel.: +82 31 299 6702; fax: +82 31 290 5644. E-mail address: [email protected] (Y.-S. Kim). 1 Present address: Department of Information Communication Engineering, Mokwon University, Daejeon 302-318, Republic of Korea. 1567-1739/$ - see front matter Ó 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.cap.2007.04.021
There are several techniques have been used for the synthesis of iron oxide nanoparticles, which including coprecipitation of ferrous (Fe2+) and ferric (Fe3+) ions by a base, usually NaOH in an aqueous solution [1,7], thermal decomposition of iron pentacarbonyl (Fe(CO)5) in the presence of oleic acid followed by oxidation [6], thermal decomposition of alkaline solution of Fe3+ chelate in the presence of hydrazine [8], and direct decomposition of FeCup3 [9]. Organic solution-phase decomposition of the iron precursor at high temperature has been widely used in iron oxide nanoparticle synthesis [3]. In this study, we have synthesized the iron oxide nanoparticles using the newly developed mechanical ultrasonication method with the FeSO4 Æ 7H2O. The FeSO4 Æ 7H2O is a low cost residuum of synthesis process of TiO2. The low cost, mass production and clean environmental process are very important issues to practical applications. Our mechanical ultrasonication method is very economic and environmentally-friendly simple process. The crystallographic
K.-C. Kim et al. / Current Applied Physics 8 (2008) 758–760
500
(311)
a
200
(511)
300
(440)
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To prepare iron oxide nanoparticles, especially magnetite (Fe3O4), 2.0 g of FeSO4 Æ 7H2O dissolved in 225 ml of the deionized (DI) water, and 60 mg of KNO3 and 0.56 g of NaOH dissolved in 90 ml of the DI water. The two solutions were heated to 75 °C and mixed the two solutions while stirring which was used a stirring rod not a magnetic stir bar. A green suspension formed and rapidly turned black. The mixed solution was heated to 90 °C for 10 min. while stirring with a stirring rod. The ultrasonication performed to prevent agglomeration which was induced from van der Waals force in the initial stage of nanoparticles formation with Ultrasonic Homogenizer (Han. Tech. Co.) at frequency 28 kHz ± 200 Hz. The black suspension was cooled to room temperature and added H2O2 for oxidation. The sodium hydroxide added to the cooled solution to neutralize and rinsed with the DI water. The suspension was dispersed and milled with the basketmilling machine. Finally the suspension was rinsed with the DI water and dried in a vacuum chamber at 80 °C for 2 h. The crystallographic structure of the as-synthesized iron oxide nanoparticles was characterized by high resolution XRD analysis (Bruker AXS, D8 Discover). The surface morphology of the powders was observed by the SEM (Philips, XL30 ESEM-FEG) and TEM. The magnetic properties of the as-synthesized nanopowders were analyzed by a VSM (Princeton Measurements, MicroMag 3900).
(220)
2. Experiment
respectively. The particle size is about 6 nm confirmed from TEM image, and the particle shape is almost a sphere confirmed by SEM and TEM images. According to the SEM and TEM images, the agglomeration is occurred very strong in the iron oxide nanopowders. The agglomeration is due to the van der Waals force between the particles. According to TEM image, the assynthesized iron oxide nanopowders are not monodispersed particles. There exist various sizes of iron oxide nanoparticles. The X-ray powder diffraction patterns of the as-synthesized iron oxide nanopowders and JCPDS reference patterns of the magnetite (Fe3O4) (No. 19-0629) are shown in Fig. 2. The XRD peaks of the as-synthesized powders are compared with those of standard magnetite data. The X-ray powder diffraction patterns of the as-synthesized
100
Intensity (CPS)
structural properties, morphology, and magnetic properties of the as-synthesized iron oxide nanopowders were investigated with various analyses including X-ray powder diffraction (XRD) analysis, scanning electron microscopy (SEM), low resolution transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) measurement.
759
0 20
30
40
50
60
70
80
2θ (degree) 0
b 20 40 60 80
3. Results and discussion 100
The SEM image and TEM image of the as-synthesized iron oxide nanopowders are shown in Fig. 1a and b,
Fig. 2. XRD patterns of the (a) as-synthesized iron oxide nanopowders and (b) JCPDS reference patterns of the Fe3O4 (No. 19-0629).
Fig. 1. (a) SEM and (b) TEM images of the as-synthesized magnetite nanopowders.
760
K.-C. Kim et al. / Current Applied Physics 8 (2008) 758–760
as-synthesized iron oxide nanoparticles (Fe3O4). According to the TEM image, was around 6 nm, and particle shape was The saturation magnetization of the iron ders was 3.7 emu/g.
5
Magnetization (emu/g)
4 3 2 1 0
were magnetite the particle size almost a sphere. oxide nanopow-
Acknowledgement
-1 -2
This work was supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD) (KRF-2005-005-J11901, KRF-2005-005J11903).
-3 -4 -5 -8000 -6000 -4000 -2000
0
2000 4000 6000 8000
Magnetic Field (Oe) Fig. 3. Hysteresis curve of the as-synthesized magnetite nanopowders.
iron oxide nanopowders are matched well with standard magnetite (Fe3O4) XRD patterns [1]. The hysteresis loop of the as-synthesized iron oxide nanopowders is shown in Fig. 3, which is measured at room temperature with a vibrating sample magnetometer. The coercivity and saturation magnetization of the as-synthesized magnetite nanopowders are 114 Oe and 3.7 emu/g, respectively. 4. Conclusions We have synthesized the iron oxide nanopowders using the newly developed mechanical ultrasonication method with the FeSO4 Æ 7H2O. The XRD patterns indicated that
References [1] Fong-Yu Cheng, Chia-Hao Su, Yu-Sheng Yang, Chen-Sheng Yeh, Chiau-Yuang Tsai, Chao-Liang Wu, Ming-Ting Wu, Dar-Bin Shieh, Biomaterials 26 (2005) 729–738. [2] Yong-kang Sun, Ming Ma, Yu Zhang, Ning Gu, Colloids Surf. A: Physicochem. Eng. Aspects 245 (2004) 15–19. [3] Shouheng Sun, Hao Zeng, J. Am. Chem. Soc. 124 (2002) 8204–8205. [4] Ho-Taek Song, Jin-sil Choi, Yong-Min Huh, Sungjun Kim, Youngwook Jun, Jin-Suck Suh, Jinwoo Cheon, J. Am. Chem. Soc. 127 (2005) 9992–9993. [5] Hyun-Seok Kim, Oh-Taek Son, Kunhong Kim, Ki-Chul Kim, SungLyul Maeng, Hyo-Il Jung, in: The 8th Korean MEMS Conference Proceedings, April 6–8, 2006, pp. 108–111. [6] Taeghwan Hyeon, Su Seong Lee, Jongnam Park, Yunhee Chung, Hyon Bin Na, J. Am. Chem. Soc. 123 (2001) 12798–12801. [7] Tcipi Fried, Gabriel Shemer, Gil Markovich, Adv. Mater. 13 (2001) 1158–1161. [8] R.S. Sapieszko, E.J. Matijevic, J. Colloid Interface Sci. 74 (1980) 405. [9] J. Rockenberger, E.C. Scher, A.P. Alivisatos, J. Am. Chem. Soc. 121 (1999) 11595–11596.
Current Applied Physics 8 (2008) 758–760 www.elsevier.com/locate/cap www.kps.or.kr
Synthesis and characterization of magnetite nanopowders Ki-Chul Kim
a,d,1
, Eung-Kwon Kim b, Jae-Won Lee c, Sung-Lyul Maeng d, Young-Sung Kim c,*
a
d
BK 21, Physics Research Division, Institute of Basic Science, Sungkyunkwan University, Suwon 440-746, Republic of Korea b School of Information and Communication Engineering, Sungkyunkwan University, Republic of Korea c Advanced Material Process of Information Technology, Sungkyunkwan University, Republic of Korea Cambridge-ETRI Joint R&D Centre, Electronics and Telecommunications Research Institute, Daejeon 305-350, Republic of Korea Received 27 July 2006; received in revised form 15 January 2007; accepted 27 April 2007 Available online 1 October 2007
Abstract We have synthesized the iron oxide nanoparticles using the newly developed mechanical ultrasonication method with the FeSO4 Æ 7H2O. We have also investigated the crystallographic structural properties, morphology, and magnetic properties of the nanopowders. According to the high resolution X-ray diffraction result, the as-synthesized iron oxide nanoparticles were magnetite (Fe3O4). The particle size of the magnetite nanoparticles was about 6 nm confirmed by transmission electron microscopy image. The particle shape was almost a sphere confirmed by scanning electron microscopy image. The coercivity and saturation magnetization of the as-synthesized iron oxide nanopowders were 114 Oe, and 3.7 emu/g, respectively. Ó 2007 Elsevier B.V. All rights reserved. PACS: 61.46.Df; 75.75.+a; 87.80.Ek Keywords: Synthesis of magnetic nanoparticles; Magnetite; Iron oxide; Mechanical ultrasonication method
1. Introduction The synthesis of the iron oxide particles has been a field intense study due to the novel properties and potentiality on the practical applications to ferrofluids, rotary shaft sealing, oscillation damping and position sensing [1–3]. The sub10 nm iron oxide nanoparticles exhibit superparamagnetic behavior, because each particle can be considered as a single magnetic domain. Superparamagnetic nanoparticles offer a high potentiality for biomedical applications, such as medical diagnosis with contrast enhancement of magnetic resonance imaging (MRI) [4], AC magnetic field-assisted cancer therapy, magnetic cell separation [5], and magnetically controlled transport of anti-cancer drugs [6]. *
Corresponding author. Tel.: +82 31 299 6702; fax: +82 31 290 5644. E-mail address: [email protected] (Y.-S. Kim). 1 Present address: Department of Information Communication Engineering, Mokwon University, Daejeon 302-318, Republic of Korea. 1567-1739/$ - see front matter Ó 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.cap.2007.04.021
There are several techniques have been used for the synthesis of iron oxide nanoparticles, which including coprecipitation of ferrous (Fe2+) and ferric (Fe3+) ions by a base, usually NaOH in an aqueous solution [1,7], thermal decomposition of iron pentacarbonyl (Fe(CO)5) in the presence of oleic acid followed by oxidation [6], thermal decomposition of alkaline solution of Fe3+ chelate in the presence of hydrazine [8], and direct decomposition of FeCup3 [9]. Organic solution-phase decomposition of the iron precursor at high temperature has been widely used in iron oxide nanoparticle synthesis [3]. In this study, we have synthesized the iron oxide nanoparticles using the newly developed mechanical ultrasonication method with the FeSO4 Æ 7H2O. The FeSO4 Æ 7H2O is a low cost residuum of synthesis process of TiO2. The low cost, mass production and clean environmental process are very important issues to practical applications. Our mechanical ultrasonication method is very economic and environmentally-friendly simple process. The crystallographic
K.-C. Kim et al. / Current Applied Physics 8 (2008) 758–760
500
(311)
a
200
(511)
300
(440)
400
(400)
To prepare iron oxide nanoparticles, especially magnetite (Fe3O4), 2.0 g of FeSO4 Æ 7H2O dissolved in 225 ml of the deionized (DI) water, and 60 mg of KNO3 and 0.56 g of NaOH dissolved in 90 ml of the DI water. The two solutions were heated to 75 °C and mixed the two solutions while stirring which was used a stirring rod not a magnetic stir bar. A green suspension formed and rapidly turned black. The mixed solution was heated to 90 °C for 10 min. while stirring with a stirring rod. The ultrasonication performed to prevent agglomeration which was induced from van der Waals force in the initial stage of nanoparticles formation with Ultrasonic Homogenizer (Han. Tech. Co.) at frequency 28 kHz ± 200 Hz. The black suspension was cooled to room temperature and added H2O2 for oxidation. The sodium hydroxide added to the cooled solution to neutralize and rinsed with the DI water. The suspension was dispersed and milled with the basketmilling machine. Finally the suspension was rinsed with the DI water and dried in a vacuum chamber at 80 °C for 2 h. The crystallographic structure of the as-synthesized iron oxide nanoparticles was characterized by high resolution XRD analysis (Bruker AXS, D8 Discover). The surface morphology of the powders was observed by the SEM (Philips, XL30 ESEM-FEG) and TEM. The magnetic properties of the as-synthesized nanopowders were analyzed by a VSM (Princeton Measurements, MicroMag 3900).
(220)
2. Experiment
respectively. The particle size is about 6 nm confirmed from TEM image, and the particle shape is almost a sphere confirmed by SEM and TEM images. According to the SEM and TEM images, the agglomeration is occurred very strong in the iron oxide nanopowders. The agglomeration is due to the van der Waals force between the particles. According to TEM image, the assynthesized iron oxide nanopowders are not monodispersed particles. There exist various sizes of iron oxide nanoparticles. The X-ray powder diffraction patterns of the as-synthesized iron oxide nanopowders and JCPDS reference patterns of the magnetite (Fe3O4) (No. 19-0629) are shown in Fig. 2. The XRD peaks of the as-synthesized powders are compared with those of standard magnetite data. The X-ray powder diffraction patterns of the as-synthesized
100
Intensity (CPS)
structural properties, morphology, and magnetic properties of the as-synthesized iron oxide nanopowders were investigated with various analyses including X-ray powder diffraction (XRD) analysis, scanning electron microscopy (SEM), low resolution transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM) measurement.
759
0 20
30
40
50
60
70
80
2θ (degree) 0
b 20 40 60 80
3. Results and discussion 100
The SEM image and TEM image of the as-synthesized iron oxide nanopowders are shown in Fig. 1a and b,
Fig. 2. XRD patterns of the (a) as-synthesized iron oxide nanopowders and (b) JCPDS reference patterns of the Fe3O4 (No. 19-0629).
Fig. 1. (a) SEM and (b) TEM images of the as-synthesized magnetite nanopowders.
760
K.-C. Kim et al. / Current Applied Physics 8 (2008) 758–760
as-synthesized iron oxide nanoparticles (Fe3O4). According to the TEM image, was around 6 nm, and particle shape was The saturation magnetization of the iron ders was 3.7 emu/g.
5
Magnetization (emu/g)
4 3 2 1 0
were magnetite the particle size almost a sphere. oxide nanopow-
Acknowledgement
-1 -2
This work was supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD) (KRF-2005-005-J11901, KRF-2005-005J11903).
-3 -4 -5 -8000 -6000 -4000 -2000
0
2000 4000 6000 8000
Magnetic Field (Oe) Fig. 3. Hysteresis curve of the as-synthesized magnetite nanopowders.
iron oxide nanopowders are matched well with standard magnetite (Fe3O4) XRD patterns [1]. The hysteresis loop of the as-synthesized iron oxide nanopowders is shown in Fig. 3, which is measured at room temperature with a vibrating sample magnetometer. The coercivity and saturation magnetization of the as-synthesized magnetite nanopowders are 114 Oe and 3.7 emu/g, respectively. 4. Conclusions We have synthesized the iron oxide nanopowders using the newly developed mechanical ultrasonication method with the FeSO4 Æ 7H2O. The XRD patterns indicated that
References [1] Fong-Yu Cheng, Chia-Hao Su, Yu-Sheng Yang, Chen-Sheng Yeh, Chiau-Yuang Tsai, Chao-Liang Wu, Ming-Ting Wu, Dar-Bin Shieh, Biomaterials 26 (2005) 729–738. [2] Yong-kang Sun, Ming Ma, Yu Zhang, Ning Gu, Colloids Surf. A: Physicochem. Eng. Aspects 245 (2004) 15–19. [3] Shouheng Sun, Hao Zeng, J. Am. Chem. Soc. 124 (2002) 8204–8205. [4] Ho-Taek Song, Jin-sil Choi, Yong-Min Huh, Sungjun Kim, Youngwook Jun, Jin-Suck Suh, Jinwoo Cheon, J. Am. Chem. Soc. 127 (2005) 9992–9993. [5] Hyun-Seok Kim, Oh-Taek Son, Kunhong Kim, Ki-Chul Kim, SungLyul Maeng, Hyo-Il Jung, in: The 8th Korean MEMS Conference Proceedings, April 6–8, 2006, pp. 108–111. [6] Taeghwan Hyeon, Su Seong Lee, Jongnam Park, Yunhee Chung, Hyon Bin Na, J. Am. Chem. Soc. 123 (2001) 12798–12801. [7] Tcipi Fried, Gabriel Shemer, Gil Markovich, Adv. Mater. 13 (2001) 1158–1161. [8] R.S. Sapieszko, E.J. Matijevic, J. Colloid Interface Sci. 74 (1980) 405. [9] J. Rockenberger, E.C. Scher, A.P. Alivisatos, J. Am. Chem. Soc. 121 (1999) 11595–11596.