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Glycine-assisted fabrication of zinc and manganese ferrite nanoparticles
Scientia Iranica F (2012) 19 (3), 930–933
Sharif University of Technology Scientia Iranica Transactions F: Nanotechnology www.sciencedirect.com
Glycine-assisted fabrication of zinc and manganese ferrite nanoparticles M. Kooti ∗ , A. Naghdi Sedeh Department of Chemistry, Shahid Chamran University, Ahvaz, Iran Received 20 November 2011; revised 16 January 2012; accepted 5 February 2012
KEYWORDS Nanoparticles; Ferrites; Glycine; Microwave; Combustion.
Abstract In this research work, we have used a microwave combustion method to synthesize three nanocrystalline ferrites including MnFe2 O4 , ZnFe2 O4 and Mn0.5 Zn0.5 Fe2 O4 . For synthesis of these ferrites, a mixture of iron (III) nitrate, zinc and/or manganese nitrate, along with glycine, as fuel, was heated in a microwave oven for a few minutes to afford the required ferrite in pure and quantitative yield. The obtained ferrites were characterized by X-ray powder Diffraction (XRD), and their mean grain size and morphology were determined by the Field Emission Scanning Electron Microscope (FESEM) and Transmission Electron Microscopy (TEM) studies. The magnetic properties of the synthesized ferrites were investigated with Vibrating Sample Magnetometry (VSM), and their hysteresis loops were obtained. The specific surface area and pore size distributions of the samples were also obtained using Brunauer–Emmett–Teller (BET) and Barrett–Joyner–Halenda (BJH) methods, respectively. © 2012 Sharif University of Technology. Production and hosting by Elsevier B.V. All rights reserved.
1. Introduction The spinel ferrites of composition MFe2 O4 (M = Co, Ni, Mn, Zn, etc.) exhibit interesting properties and, therefore, have wide potential technological applications in various fields [1–3]. Ferrites have the general formula of AB2 O4 , where A and B sites have tetrahedral and octahedral coordination, respectively. Depending on the kind of cations occupying the A-site and the B-site, these spinel-type ferrites may show different magnetic behavior [4]. In fact, their magnetic properties can be systematically varied by changing the identity or partial substitution of the divalent M2+ cation, while maintaining the basic crystal structure. MnFe2 O4 , ZnFe2 O4 and mixed Mn–Zn ferrites (Mnx Zn1−x Fe2 O4 ) have been intensively studied because of their fascinating magnetic and electromagnetic properties, as well as their chemical stability, resistance to corrosion and reasonable cost [5,6]. Several synthesis approaches have been developed
∗
Corresponding author. E-mail address: [email protected] (M. Kooti). Peer review under responsibility of Sharif University of Technology.
to prepare these ferrite nanoparticles, so far [7–12]. Among the various methods of synthesis for ferrite nanoparticles, the auto-combustion synthesis method has attracted considerable attention in recent years [13,14]. This is mainly because of its inexpensive precursors, short preparation time, and relatively simple manipulations. We have, therefore, used the autocombustion method to prepare three ferrite nanoparticles by microwave heating. Glycine was used as a fuel in our procedure, which maintains a sustainable combustion reaction leading to the production of MnFe2 O4 , ZnFe2 O4 and Zn0.5 Mn0.5 Fe2 O4 nanoparticles. 2. Experimental procedure The MnFe2 O4 and ZnFe2 O4 ferrites were prepared by mixing zinc or manganese and iron(III) nitrates with glycine in 1: 2: 6 molar ratios, respectively (for Mn0.5 Zn0.5 Fe2 O4 , the molar ratios of zinc nitrate, manganese nitrate, iron(III) nitrate and glycine were 0.5: 0.5: 2: 6). The mixture was heated in a microwave oven with 30% power for 3 min using a porcelain crucible as the container. The crystal water was gradually vaporized during heating. Then, a great deal of foam was produced and sparks appeared that spread through the mass, yielding a dark brown, voluminous, fluffy product in the container. The product, in each case, was washed with distilled water and ethanol and then dried at 100 °C in an oven for 2 h. The MnFe2 O4 , ZnFe2 O4 and Mn0.5 Zn0.5 Fe2 O4 ferrites were obtained as black, brownish yellow and brown powders, respectively.
1026-3098 © 2012 Sharif University of Technology. Production and hosting by Elsevier B.V. All rights reserved. doi:10.1016/j.scient.2012.02.020
M. Kooti, A.N. Sedeh / Scientia Iranica, Transactions F: Nanotechnology 19 (2012) 930–933
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Figure 1: XRD patterns of as-prepared ferrites (a) MnFe2 O4 , (b) Mn0.5 Zn0.5 Fe2 O4 , and (c) ZnFe2 O4 .
3. Results and discussion The X-ray diffraction patterns of the as-synthesized ferrite nanoparticles are shown in Figure 1. All diffraction lines for Zn, Mn and mixed Mn-Zn ferrites could be indexed within the spinel type lattice with the Fd3m space group (JCPDS files no. 22-1012, 10-0319 and 82-1049). The crystallite size of these ferrites was estimated to be about 41 nm from the X-ray peak broadening of the (311) peak using Scherrer’s equation. The X-ray patterns of the three prepared ferrites display sharp and well-resolved diffraction peaks, revealing the good crystallinity of the specimens. No additional peak of the impurity phase was observed in the XRD patterns, showing that the prepared ferrites are pure. The molar ratio of the metals in the three as-synthesized ferrites was confirmed by atomic absorption analysis. The percent of each metal in these ferrites was determined by this analysis and the results confirmed their stoichiometric formulas. The morphology and particle sizes of the as-prepared Zn, Mn and mixed Mn–Zn ferrites were determined by FESEM and TEM techniques. As can be seen in Figure 2, the FESEM images show the presence of voids and pores in the samples, which can be attributed to the release of large amounts of gas during the combustion process. The samples have a spongy structure and one can see that the formation of multigrain agglomerations consisted of very fine crystallite. The TEM micrographs of the as-fabricated three ferrite nanoparticles are given in Figure 3, showing almost homogeneous and uniform distribution of these particles in the powder samples. The particles consist of some regular and irregular polyhedrons with mean sizes of about 25 nm, much smaller than the sizes obtained from the XRD measurements. Magnetic measurements of the samples were carried out at room temperature using a vibrating sample magnetometer (VSM) with a peak field of 10 kOe, and the hysteresis loops for Zn, Mn and Mn–Zn nanoferrites are shown in Figure 4. As clearly shown, the variation of magnetization as a function of the applied field presents a narrow cycle and the observed hysteresis loops are a characteristic behavior of soft magnetic materials. The saturation magnetization (Ms ), remanence magnetization (Mr ) and coercivity (Hc ) values of these ferrites are given in Table 1. The Ms of Mn0.5 Zn0.5 Fe2 O4 is higher than the Ms reported for Mn0.6 Zn0.4 Fe2 O4 , which was 52.4 emu/g [15], but lower than that of the bulk mixed ferrite [16]. The magnetic properties of the mixed Mnx Zn1−x Fe2 O4 system were found to be influenced by a number of factors, such as size of particles, concentration of divalent cations (Zn2+ and Mn2+ ) in the ferrite and, also, occupation of octahedral sites by these cations [17]. These
Figure 2: FESEM images of (a) ZnFe2 O4 , (b) MnFe2 O4 , and (c) Mn0.5 Zn0.5 Fe2 O4 nanoparticles. Table 1: Magnetic property of the as-fabricated ferrites nanoparticles. Sample MnFe2 O4 ZnFe2 O4 Zn0.5 Fe2 O4 Mn0.5
(Ms ) emu/g 79.98 50.43 84.04
(Mr ) emu/g 10.17 11.50 20.80
(Hc ) Oe 72.63 43.16 56.86
factors are mainly controlled by the methods used for the synthesis of Mn–Zn ferrite [18]. The observed values of Ms for the prepared MnFe2 O4 and ZnFe2 O4 are also higher than those reported for these ferrites [19]. The low temperature N2 adsorption and desorption isotherms of the as-prepared ferrites were obtained and, for all of them, a type VI isotherm with a narrow hysteresis loop is observed at a relatively high pressure range, implying the presence of typical mesoporous solids [20]. The specific surface area of these nanoparticles was also calculated by the BET equation and pore size distributions were calculated from the desorption branch using the BJH method. The BET total surface areas for MnFe2 O4 , Mn0.5 Zn0.5 Fe2 O4 and ZnFe2 O4 were 11.09, 6.60 and 3.5 m2 /g, respectively. The mean pore diameter for these
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M. Kooti, A.N. Sedeh / Scientia Iranica, Transactions F: Nanotechnology 19 (2012) 930–933
Figure 5: N2 adsorption/desorption isotherms of MnFe2 O4 nanoparticles.
Figure 3: TEM micrographs of (a) ZnFe2 O4 , (b) MnFe2 O4 , and (c) Mn0.5 Zn0.5 Fe2 O4 nanoparticles.
Figure 6: BJH plot of MnFe2 O4 nanoparticles.
Figure 4: Hysteresis loops of as-prepared ZnFe2 O4 (a), MnFe2 O4 (b), and Mn0.5 Zn0.5 Fe2 O4 (c) nanoparticles.
three ferrites was found to be 21.882, 40.305 and 27.157 nm. The nitrogen adsorption–desorption isotherms and BJH plot of MnFe2 O4 are shown in Figures 5 and 6, respectively. The other two synthesized ferrites (ZnFe2 O4 and Mn0.5 Zn0.5 Fe2 O4 ) show more or less the same BET and BJH plots, and are not given here. It has been reported that the surface area and particle diameter of the ferrites vary drastically with the temperature of reaction [21,22]. At higher temperatures, the specific surface area
decreases and the particle diameter decreases. The observed low specific surface area for the samples prepared in our procedure may be attributed to the high temperature of the reaction in the microwave. The magnetic property of these ferrites may be another factor responsible for the decrease in surface area, since they tend to aggregate, and the large agglomerated particles will have low surface area. 4. Conclusions In this study, three nanosized ferrites, MnFe2 O4 , ZnFe2 O4 and Mn0.5 Zn0.5 Fe2 O4 , have been successfully prepared by a
M. Kooti, A.N. Sedeh / Scientia Iranica, Transactions F: Nanotechnology 19 (2012) 930–933
facile microwave-assisted combustion method using glycine as a fuel. This method yields fine ferrite particles of about 25 nm, determined by TEM analysis. The magnetic properties of these ferrites were studied by VSM. Nitrogen sorption measurements revealed that the as-prepared ferrites are typical mesoporous solids. Our procedure provides a simple and rapid method for the preparation of nanoscaled ferrites, using inexpensive precursors, and this method can probably be applied for the synthesis of other ferrites. Acknowledgment The authors are grateful for the support provided by the Research Council of Shahid Chamran University, Ahvaz, Iran. References [1] Goldman, A., Modern Ferrite Technology, 2nd Edn., Springer, New York (2006). [2] Alone, S.T., Shirsath, Sagar E., Kadam, R.H. and Jadhav, K.M. ‘‘Chemical synthesis, structural and magnetic properties of nano-structured Co–Zn–Fe–Cr ferrite’’, J. Alloys Compd., 509, pp. 5055–5060 (2011). [3] Hu, P., Yang, H.B., Pan, D.A., Wang, H., Tian, J.J., Zhang, S.G., Wang, X.F. and Volinsky, A.A. ‘‘Heat treatment effects on microstructure and magnetic properties of Mn–Zn ferrite powders’’, J. Magn. Magn. Mater., 322, pp. 173–177 (2010). [4] Akther Hossain, A.K.M., Tabata, H. and Kawai, T. ‘‘Magnetoresistive properties of Zn1−x Cox Fe2 O4 ferrites’’, J. Magn. Magn. Mater., 320, pp. 1157–1162 (2008). [5] Cheng, P., Li, W., Zhou, T., Jin, Y. and Gu, M. ‘‘Physical and photocatalytic properties of zinc ferrite doped titania under visible light irradiation’’, J. Photochem. Photobiol. A, 168, pp. 97–101 (2004). [6] Scarberry, K.E., Dickerson, E.B., McDonald, J.F. and Zhang, Z.J. ‘‘Magnetic nanoparticle-peptide conjugates for in vitro and in vivo targeting and extraction of cancer cells’’, J. Am. Chem. Soc., 130, pp. 10258–10262 (2008). [7] Goodarz Naseri, M., Bin Saion, E., Abbastabar Ahangar, H., Hashim, M. and Shaari, A.H. ‘‘Synthesis and characterization of manganese ferrite nanoparticles by thermal treatment method’’, J. Magn. Magn. Mater., 323, pp. 1745–1749 (2011). [8] Mathew, D.S. and Juang, R.S. ‘‘An overview of the structure and magnetism of spinel ferrite nanoparticles and their synthesis in microemulsions’’, Chem. Eng. J., 129, pp. 51–65 (2007). [9] Angermann, A. and Topfer, J. ‘‘Synthesis of nanocrystalline Mn–Zn ferrite powders through thermolysis of mixed oxalates’’, Ceram. Int., 37, pp. 995–1002 (2011). [10] Fierro, G., Lo Jacono, M., Dragone, R., Ferraris, G., Andreozzi, G.B. and Graziani, G. ‘‘Fe–Zn manganite spinels and their carbonate precursors: preparation, characterization and catalytic activity’’, Appl. Catal. B: Environ., 57, pp. 153–165 (2005).
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[11] Bao, N., Shen, L., Wang, Y., Padhan, P. and Gupta, A. ‘‘A facile thermolysis route to monodisperse ferrite nanocrystals’’, J. Am. Chem. Soc., 129, pp. 12374–12375 (2007). [12] Hou, X., Feng, J., Ren, Y., Fan, Z. and Zhang, M. ‘‘Synthesis and adsorption properties of sponge like porous MnFe2 O4 ’’, Colloids Surf. A, 363, pp. 1–7 (2010). [13] Deraz, N.M. ‘‘Glycine-assisted fabrication of nanocrystalline cobalt ferrite system’’, J. Anal. Appl. Pyrol., 88, pp. 103–109 (2010). [14] Alarifi, A., Deraz, N.M. and Shaban, S. ‘‘Structural, morphological and magnetic properties of NiFe2 O4 nano-particles’’, J. Alloys Compd., 486, pp. 501–506 (2009). [15] Zhang, Q., Zhu, M., Zhang, Q., Li, Y. and Wang, H. ‘‘Fabrication and magnetic property analysis of monodisperse manganese–zinc ferrite nanospheres’’, J. Magn. Magn. Mater., 321, pp. 3203–3206 (2009). [16] Rath, C., Anand, S., Das, R.P., Sahu, K.K., Kulkarni, S.D., Date, S.K. and Mishra, N.C. ‘‘Dependence on cation distribution of particle size, lattice parameter, and magnetic properties in nanosize Mn–Zn ferrite’’, J. Appl. Phys., 91, pp. 2211–2215 (2002). [17] Beji, Z., Smiri, L.S., Yaacoub, N., Greneche, J.M., Menguy, N., Ammar, S. and Fievet, F. ‘‘Annealing effect on the magnetic properties of polyol-made Ni–Zn ferrite nanoparticles’’, Chem. Mater., 22, pp. 1350–1366 (2010). [18] Auzans, E., Zins, D., Blums, E. and Massart, R. ‘‘Synthesis and properties of Mn–Zn ferrite ferrofluids’’, J. Mater. Sci., 34, pp. 1253–1260 (1999). [19] Pradeep, A., Priyadharsini, A.P. and Chandrasekaran, G. ‘‘Structural, magnetic and electrical properties of nanocrystalline zinc ferrite’’, J. Alloys Compd., 509, pp. 3917–3923 (2011). [20] Gregg, S.J. and Sing, K.S.W., Adsorption, Surface Area and Porosity, Academic Press, New York (1982). [21] Li, Q., Bo, C. and Wang, W. ‘‘Preparation and magnetic properties of ZnFe2 O4 nanofibers by coprecipitation-air oxidation method’’, Mater. Chem. Phys., 124, pp. 891–893 (2010). [22] Angermann, A., Topfer, J., da Silva, K.L. and Becker, K.D. ‘‘Nanocrystalline Mn–Zn ferrites from mixed oxalates: synthesis, stability and magnetic properties’’, J. Alloys Compd., 508, pp. 433–439 (2010).
Mohammad Kooti received his Ph.D. degree in Inorganic Chemistry from Sussex University, England, in 1975. He then joined the faculty at Shahid Chamran University, Ahvaz, Iran, where he is now Professor of Inorganic Chemistry, and where he instructs and supervises B.S., M.S. and Ph.D. degree students in this subject. His research interests include the synthesis of ferrites magnetic nanoparticles and their potential applications as adsorbents, antibacterial agents, magnetic nanoparticles catalyst and etc.
Azar Naghdi Sedeh received her B.S. degree in Chemistry in 2008 and her M.S. degree in Inorganic Chemistry in 2011, both from Shahid Chamran University, Ahvaz, Iran. Her research interests include the synthesis of various magnetic ferrites nanoparticles by the microwave route, and the study of their properties. She has so far presented 7 papers at national and international conferences and submitted a number of papers for publication in journals. Ms Naghdi Sedeh is now teaching Chemistry and undertaking research at the Production Technology Research Institute of Ahvaz.
Sharif University of Technology Scientia Iranica Transactions F: Nanotechnology www.sciencedirect.com
Glycine-assisted fabrication of zinc and manganese ferrite nanoparticles M. Kooti ∗ , A. Naghdi Sedeh Department of Chemistry, Shahid Chamran University, Ahvaz, Iran Received 20 November 2011; revised 16 January 2012; accepted 5 February 2012
KEYWORDS Nanoparticles; Ferrites; Glycine; Microwave; Combustion.
Abstract In this research work, we have used a microwave combustion method to synthesize three nanocrystalline ferrites including MnFe2 O4 , ZnFe2 O4 and Mn0.5 Zn0.5 Fe2 O4 . For synthesis of these ferrites, a mixture of iron (III) nitrate, zinc and/or manganese nitrate, along with glycine, as fuel, was heated in a microwave oven for a few minutes to afford the required ferrite in pure and quantitative yield. The obtained ferrites were characterized by X-ray powder Diffraction (XRD), and their mean grain size and morphology were determined by the Field Emission Scanning Electron Microscope (FESEM) and Transmission Electron Microscopy (TEM) studies. The magnetic properties of the synthesized ferrites were investigated with Vibrating Sample Magnetometry (VSM), and their hysteresis loops were obtained. The specific surface area and pore size distributions of the samples were also obtained using Brunauer–Emmett–Teller (BET) and Barrett–Joyner–Halenda (BJH) methods, respectively. © 2012 Sharif University of Technology. Production and hosting by Elsevier B.V. All rights reserved.
1. Introduction The spinel ferrites of composition MFe2 O4 (M = Co, Ni, Mn, Zn, etc.) exhibit interesting properties and, therefore, have wide potential technological applications in various fields [1–3]. Ferrites have the general formula of AB2 O4 , where A and B sites have tetrahedral and octahedral coordination, respectively. Depending on the kind of cations occupying the A-site and the B-site, these spinel-type ferrites may show different magnetic behavior [4]. In fact, their magnetic properties can be systematically varied by changing the identity or partial substitution of the divalent M2+ cation, while maintaining the basic crystal structure. MnFe2 O4 , ZnFe2 O4 and mixed Mn–Zn ferrites (Mnx Zn1−x Fe2 O4 ) have been intensively studied because of their fascinating magnetic and electromagnetic properties, as well as their chemical stability, resistance to corrosion and reasonable cost [5,6]. Several synthesis approaches have been developed
∗
Corresponding author. E-mail address: [email protected] (M. Kooti). Peer review under responsibility of Sharif University of Technology.
to prepare these ferrite nanoparticles, so far [7–12]. Among the various methods of synthesis for ferrite nanoparticles, the auto-combustion synthesis method has attracted considerable attention in recent years [13,14]. This is mainly because of its inexpensive precursors, short preparation time, and relatively simple manipulations. We have, therefore, used the autocombustion method to prepare three ferrite nanoparticles by microwave heating. Glycine was used as a fuel in our procedure, which maintains a sustainable combustion reaction leading to the production of MnFe2 O4 , ZnFe2 O4 and Zn0.5 Mn0.5 Fe2 O4 nanoparticles. 2. Experimental procedure The MnFe2 O4 and ZnFe2 O4 ferrites were prepared by mixing zinc or manganese and iron(III) nitrates with glycine in 1: 2: 6 molar ratios, respectively (for Mn0.5 Zn0.5 Fe2 O4 , the molar ratios of zinc nitrate, manganese nitrate, iron(III) nitrate and glycine were 0.5: 0.5: 2: 6). The mixture was heated in a microwave oven with 30% power for 3 min using a porcelain crucible as the container. The crystal water was gradually vaporized during heating. Then, a great deal of foam was produced and sparks appeared that spread through the mass, yielding a dark brown, voluminous, fluffy product in the container. The product, in each case, was washed with distilled water and ethanol and then dried at 100 °C in an oven for 2 h. The MnFe2 O4 , ZnFe2 O4 and Mn0.5 Zn0.5 Fe2 O4 ferrites were obtained as black, brownish yellow and brown powders, respectively.
1026-3098 © 2012 Sharif University of Technology. Production and hosting by Elsevier B.V. All rights reserved. doi:10.1016/j.scient.2012.02.020
M. Kooti, A.N. Sedeh / Scientia Iranica, Transactions F: Nanotechnology 19 (2012) 930–933
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Figure 1: XRD patterns of as-prepared ferrites (a) MnFe2 O4 , (b) Mn0.5 Zn0.5 Fe2 O4 , and (c) ZnFe2 O4 .
3. Results and discussion The X-ray diffraction patterns of the as-synthesized ferrite nanoparticles are shown in Figure 1. All diffraction lines for Zn, Mn and mixed Mn-Zn ferrites could be indexed within the spinel type lattice with the Fd3m space group (JCPDS files no. 22-1012, 10-0319 and 82-1049). The crystallite size of these ferrites was estimated to be about 41 nm from the X-ray peak broadening of the (311) peak using Scherrer’s equation. The X-ray patterns of the three prepared ferrites display sharp and well-resolved diffraction peaks, revealing the good crystallinity of the specimens. No additional peak of the impurity phase was observed in the XRD patterns, showing that the prepared ferrites are pure. The molar ratio of the metals in the three as-synthesized ferrites was confirmed by atomic absorption analysis. The percent of each metal in these ferrites was determined by this analysis and the results confirmed their stoichiometric formulas. The morphology and particle sizes of the as-prepared Zn, Mn and mixed Mn–Zn ferrites were determined by FESEM and TEM techniques. As can be seen in Figure 2, the FESEM images show the presence of voids and pores in the samples, which can be attributed to the release of large amounts of gas during the combustion process. The samples have a spongy structure and one can see that the formation of multigrain agglomerations consisted of very fine crystallite. The TEM micrographs of the as-fabricated three ferrite nanoparticles are given in Figure 3, showing almost homogeneous and uniform distribution of these particles in the powder samples. The particles consist of some regular and irregular polyhedrons with mean sizes of about 25 nm, much smaller than the sizes obtained from the XRD measurements. Magnetic measurements of the samples were carried out at room temperature using a vibrating sample magnetometer (VSM) with a peak field of 10 kOe, and the hysteresis loops for Zn, Mn and Mn–Zn nanoferrites are shown in Figure 4. As clearly shown, the variation of magnetization as a function of the applied field presents a narrow cycle and the observed hysteresis loops are a characteristic behavior of soft magnetic materials. The saturation magnetization (Ms ), remanence magnetization (Mr ) and coercivity (Hc ) values of these ferrites are given in Table 1. The Ms of Mn0.5 Zn0.5 Fe2 O4 is higher than the Ms reported for Mn0.6 Zn0.4 Fe2 O4 , which was 52.4 emu/g [15], but lower than that of the bulk mixed ferrite [16]. The magnetic properties of the mixed Mnx Zn1−x Fe2 O4 system were found to be influenced by a number of factors, such as size of particles, concentration of divalent cations (Zn2+ and Mn2+ ) in the ferrite and, also, occupation of octahedral sites by these cations [17]. These
Figure 2: FESEM images of (a) ZnFe2 O4 , (b) MnFe2 O4 , and (c) Mn0.5 Zn0.5 Fe2 O4 nanoparticles. Table 1: Magnetic property of the as-fabricated ferrites nanoparticles. Sample MnFe2 O4 ZnFe2 O4 Zn0.5 Fe2 O4 Mn0.5
(Ms ) emu/g 79.98 50.43 84.04
(Mr ) emu/g 10.17 11.50 20.80
(Hc ) Oe 72.63 43.16 56.86
factors are mainly controlled by the methods used for the synthesis of Mn–Zn ferrite [18]. The observed values of Ms for the prepared MnFe2 O4 and ZnFe2 O4 are also higher than those reported for these ferrites [19]. The low temperature N2 adsorption and desorption isotherms of the as-prepared ferrites were obtained and, for all of them, a type VI isotherm with a narrow hysteresis loop is observed at a relatively high pressure range, implying the presence of typical mesoporous solids [20]. The specific surface area of these nanoparticles was also calculated by the BET equation and pore size distributions were calculated from the desorption branch using the BJH method. The BET total surface areas for MnFe2 O4 , Mn0.5 Zn0.5 Fe2 O4 and ZnFe2 O4 were 11.09, 6.60 and 3.5 m2 /g, respectively. The mean pore diameter for these
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M. Kooti, A.N. Sedeh / Scientia Iranica, Transactions F: Nanotechnology 19 (2012) 930–933
Figure 5: N2 adsorption/desorption isotherms of MnFe2 O4 nanoparticles.
Figure 3: TEM micrographs of (a) ZnFe2 O4 , (b) MnFe2 O4 , and (c) Mn0.5 Zn0.5 Fe2 O4 nanoparticles.
Figure 6: BJH plot of MnFe2 O4 nanoparticles.
Figure 4: Hysteresis loops of as-prepared ZnFe2 O4 (a), MnFe2 O4 (b), and Mn0.5 Zn0.5 Fe2 O4 (c) nanoparticles.
three ferrites was found to be 21.882, 40.305 and 27.157 nm. The nitrogen adsorption–desorption isotherms and BJH plot of MnFe2 O4 are shown in Figures 5 and 6, respectively. The other two synthesized ferrites (ZnFe2 O4 and Mn0.5 Zn0.5 Fe2 O4 ) show more or less the same BET and BJH plots, and are not given here. It has been reported that the surface area and particle diameter of the ferrites vary drastically with the temperature of reaction [21,22]. At higher temperatures, the specific surface area
decreases and the particle diameter decreases. The observed low specific surface area for the samples prepared in our procedure may be attributed to the high temperature of the reaction in the microwave. The magnetic property of these ferrites may be another factor responsible for the decrease in surface area, since they tend to aggregate, and the large agglomerated particles will have low surface area. 4. Conclusions In this study, three nanosized ferrites, MnFe2 O4 , ZnFe2 O4 and Mn0.5 Zn0.5 Fe2 O4 , have been successfully prepared by a
M. Kooti, A.N. Sedeh / Scientia Iranica, Transactions F: Nanotechnology 19 (2012) 930–933
facile microwave-assisted combustion method using glycine as a fuel. This method yields fine ferrite particles of about 25 nm, determined by TEM analysis. The magnetic properties of these ferrites were studied by VSM. Nitrogen sorption measurements revealed that the as-prepared ferrites are typical mesoporous solids. Our procedure provides a simple and rapid method for the preparation of nanoscaled ferrites, using inexpensive precursors, and this method can probably be applied for the synthesis of other ferrites. Acknowledgment The authors are grateful for the support provided by the Research Council of Shahid Chamran University, Ahvaz, Iran. References [1] Goldman, A., Modern Ferrite Technology, 2nd Edn., Springer, New York (2006). [2] Alone, S.T., Shirsath, Sagar E., Kadam, R.H. and Jadhav, K.M. ‘‘Chemical synthesis, structural and magnetic properties of nano-structured Co–Zn–Fe–Cr ferrite’’, J. Alloys Compd., 509, pp. 5055–5060 (2011). [3] Hu, P., Yang, H.B., Pan, D.A., Wang, H., Tian, J.J., Zhang, S.G., Wang, X.F. and Volinsky, A.A. ‘‘Heat treatment effects on microstructure and magnetic properties of Mn–Zn ferrite powders’’, J. Magn. Magn. Mater., 322, pp. 173–177 (2010). [4] Akther Hossain, A.K.M., Tabata, H. and Kawai, T. ‘‘Magnetoresistive properties of Zn1−x Cox Fe2 O4 ferrites’’, J. Magn. Magn. Mater., 320, pp. 1157–1162 (2008). [5] Cheng, P., Li, W., Zhou, T., Jin, Y. and Gu, M. ‘‘Physical and photocatalytic properties of zinc ferrite doped titania under visible light irradiation’’, J. Photochem. Photobiol. A, 168, pp. 97–101 (2004). [6] Scarberry, K.E., Dickerson, E.B., McDonald, J.F. and Zhang, Z.J. ‘‘Magnetic nanoparticle-peptide conjugates for in vitro and in vivo targeting and extraction of cancer cells’’, J. Am. Chem. Soc., 130, pp. 10258–10262 (2008). [7] Goodarz Naseri, M., Bin Saion, E., Abbastabar Ahangar, H., Hashim, M. and Shaari, A.H. ‘‘Synthesis and characterization of manganese ferrite nanoparticles by thermal treatment method’’, J. Magn. Magn. Mater., 323, pp. 1745–1749 (2011). [8] Mathew, D.S. and Juang, R.S. ‘‘An overview of the structure and magnetism of spinel ferrite nanoparticles and their synthesis in microemulsions’’, Chem. Eng. J., 129, pp. 51–65 (2007). [9] Angermann, A. and Topfer, J. ‘‘Synthesis of nanocrystalline Mn–Zn ferrite powders through thermolysis of mixed oxalates’’, Ceram. Int., 37, pp. 995–1002 (2011). [10] Fierro, G., Lo Jacono, M., Dragone, R., Ferraris, G., Andreozzi, G.B. and Graziani, G. ‘‘Fe–Zn manganite spinels and their carbonate precursors: preparation, characterization and catalytic activity’’, Appl. Catal. B: Environ., 57, pp. 153–165 (2005).
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Mohammad Kooti received his Ph.D. degree in Inorganic Chemistry from Sussex University, England, in 1975. He then joined the faculty at Shahid Chamran University, Ahvaz, Iran, where he is now Professor of Inorganic Chemistry, and where he instructs and supervises B.S., M.S. and Ph.D. degree students in this subject. His research interests include the synthesis of ferrites magnetic nanoparticles and their potential applications as adsorbents, antibacterial agents, magnetic nanoparticles catalyst and etc.
Azar Naghdi Sedeh received her B.S. degree in Chemistry in 2008 and her M.S. degree in Inorganic Chemistry in 2011, both from Shahid Chamran University, Ahvaz, Iran. Her research interests include the synthesis of various magnetic ferrites nanoparticles by the microwave route, and the study of their properties. She has so far presented 7 papers at national and international conferences and submitted a number of papers for publication in journals. Ms Naghdi Sedeh is now teaching Chemistry and undertaking research at the Production Technology Research Institute of Ahvaz.