FT-IR, XRD, and SEM Study of CoFe2O4 Nanoparticles by Chemical Co-Precipitation Method

Transcription

1 NANO VISION, Vol.5(4-6), , April-June 2015 (An International Research Journal of Nano Science & Technology), ISSN (Print) ISSN (Online) FT-IR, XRD, and SEM Study of CoFe2O4 Nanoparticles by Chemical Co-Precipitation Method S. Sathiya 1, K. Parasuraman 1, M. Anbarasu 2 and K. Balamurugan 3 1 Department of Physics, Poompuhar College, Melaiyur, Tamilnadu, INDIA. 2 Department of Physics, Annai College of Arts and Science, Kumbakonam, Tamilnadu, INDIA. 3 Department of Physics, Annamalai University, Annamalainagar, Tamilnadu, INDIA. parasu1959@gmail.com. Presented in Second National Conference on Thin Film Science and Nano Technology (SECOND-NCTFSANT-2015) March 2-3, 2015, Rajah Serfoji Govt. College, Thanjavur, T.N. (India). ABSTRACT CoFe 2 O 4 nanoparticles were prepared by chemical co-precipitation method. The CoFe 2 O 4 nanoparticles prepared using Cobalt Chloride, Ferrous Chloride and NH 4 (15ml) solution. The crystallite size and phase were determined by X-ray diffraction spectroscopy (XRD). Scanning Electron Microscopy (SEM) was used for determining morphology evaluation of nanoparticles. The presence of functional groups of the nanoparticles was measured by Fourier transform infrared spectroscopy (FTIR), which gives the evidence of formation CoFe 2 O 4 Nanoparticles. Keywords: CoFe 2 O 4, nanoparticles, chemical co-precipitation. 1. INTRODUCTION Cobalt ferrite (CoFe 2 O 4 ) is a cubic ferrite with an inverse spinel structure where Co 2+ ions are located in B sites and Fe 3+ in the A and B sites. Microcrystalline ferrites form the basis of materials currently used for magnetic information recording and storage 1-3. To increase the recorded information density, it seems reasonable to obtain nano crystalline ferrites and to prepare magnetic carriers based on them. Grinding of microcrystalline ferrite powders to reach the nano size of grains is efficient, as this gives particles with a broad size distribution, the content of the fraction with the optimal particle size (30 50 nm) being relatively low 4. Nano structured ferrite exhibits unusual physical and chemical properties, which are significantly different from those of conventional bulk materials, due to its extremely small grain size or large specific surface area. Therefore, the preparation and characterization of the nano crystalline ferrite powder have gained more attention recently.

2 134 S. Sathiya, et al., Nano Vision, Vol.5 (4-6), (2015) Inverse spinel ferrites, such as CoFe 2 O 4, are well known hard magnetic materials with very high cubic magneto crystalline anisotropy, high coercivity, and moderate saturation magnetization 5. These properties make it a promising material for high-density magnetic storage. Conventional methods of nickel nanoferrites production include mechanosynthesis 6, co-precipitation 7,8, sol-gel 9,10 and solvothermal method 11. The magnetic behavior of these nanoparticles depends mainly on the synthesis route 12,13. However, the development and fabrication of nickel ferrite nanoparticles with controlled size and controlled morphology and therefore improved properties, remains an important challenge. In this study, Fe 3 O 4 nanoparticles were prepared by co-precipitation method. One of the aims was to develop a general synthetic method and explore the structural properties of the Fe 3 O 4 nanoparticles. 2. EXPERIMENTAL METHODS 2.1 Preparation of Cobalt ferrite (CoFe 2 O 4 ) nanoparticles Cobalt ferrite (CoFe 2 O 4 ) nanoparticles were synthesized by the Co-precipitation method. All chemical reagents used as starting materials are of analytical grade and purchased without any further purification. In a typical synthesis process, 0.05M of ferrous Chloride (Fe 2 Cl 3 ) was dissolved in 100 ml aqueous solution under vigorous stirring to form a clear solution, and then 0.25M of Cobalt Chloride (CoCl 2 ) and 15ml of ammonia (NH 3 ) solution were added to the above solution. This mixture was then vigorously stirred at room temperature for 3 hours to form a homogeneous solution. Then the solutions were mixed suddenly green colour appears and continue to stirring the solution colour changed into black and the precipitate was immediately produced. After stirring for 3hr, the precipitate was filtered. The precipitate was washed with double distilled water several times to remove the excess amine molecules. The CoFe 2 O 4 nanoparticles were finally collected as a black powder after drying at room temperature Characterization Prepared CoFe 2 O 4 nanoparticles were characterized by various techniques. The structural characterization was performed using a Philip X PERT-PRO diffractometer system. Cu K α line with wavelength of Å is generated with a setting of 30 mill amperes and 40 kv with the electrode is used for diffraction with CuKα radiation. The infrared spectra of prepared samples were recorded in the vibrational frequency ranging from 4000 to 400 cm -1 using a JASCO 460 plus FTIR spectrometer. Size and shape of the particles were determined using Scanning electron microscopy (SEM JSM-5610) analysis. 3. RESULTS AND DISCUSSION 3.1. X-ray diffraction analysis The XRD pattern of CoFe 2 O 4 nanoparticles prepared at room temperature is shown in Fig.1. The XRD data clearly confirm the polycrystalline spinel structures of cobalt ferrite

3 S. Sathiya, et al., Nano Vision, Vol.5 (4-6), (2015) 135 (CoFe2O4) diffraction peaks are consistent with the standard pattern for JCPDS Card No For the prepared CoFe 2 O 4 nanoparticles have the most intensive lines (311), (440) and (511) are observed the diffraction peak indicated at 2θ= , and The XRD pattern shows the prepared nanoparticles are in a cubic structure of CoFe 2 O 4. From this observation, it can be seen that the product is high crystalline and no characteristics peaks are observed from the impurities. The observed peaks and structure are good agreement with the standard reported values. The crystallite size of the CoFe 2 O 4 product is determined by using Debye Scherrer s formula 14, D = k / β Cosθ Where, K=0.89 is the shape factor, λ is the X-ray wavelength of CuKα radiation, β is the full width at half maximum (FWHM) of the peaks and θ is the glancing angle and the average crystallite size is 23 nm. Fig.1: X-ray diffraction pattern of CoFe2O4 nanoparticles synthesized by Co-precipitation method 3.2. Fourier Transform Infrared (FT-IR) spectral Analysis FT-IR spectra (Fig.2) of CoFe 2 O 4 clearly shows an absorption bands around 3432 cm 1, which are characteristic stretching vibration of hydroxyl functional group(o-h) on the surface of nanoparticles or adsorbed water in the sample. The absorption band at 1734 cm 1 corresponds to stretching vibration of carbonyl group (C-O). The stretching vibration of the carboxylate group (C=O) is observed around cm 1. The stretching vibration of C=C group also localized at 1632 cm 1. The absorption band around 1100 cm 1 is assigned the stretching vibration of C-C-C group [21]. The above observed FTIR spectra confirm the presence of organic impurities in the sample during the preparation conditions. In addition, two absorption bands at 574 cm 1 and 438 cm 1 are corresponding to the vibration of tetrahedral and octahedral complexes respectively, which are indicative of formation of spinel ferrite structure. As can be seen from the spectra, the normal mode of vibration of tetrahedral cluster (574 cm 1 ) is higher than that of octahedral cluster (438 cm 1 ). This can be due to the shorter bond length of tetrahedral cluster than the octahedral cluster 15. Nano Vision Vol. 5, Issue 4-6, April-June, 2015 (Pages )

4 136 S. Sathiya, et al., Nano Vision, Vol.5 (4-6), (2015) Fig. 2: Fourier Transform - Infrared (FTIR) spectrum of CoFe2O4 nanoparticles 3.3. Surface morphology Analysis Fig.3 shows the SEM micrographs clearly show the surface features, by which it highlight that cobalt ferrite nanoparticle was successfully prepared. It is cleared that the tested particles are spherical in shape with a narrow size distribution and their particle sizes are 24 nm which is approximately the size calculated by the Debye Scherrer formula. From the SEM results, the prepared crystallites are nearly spherical in shape and it can be seen that the particles agglomeration, indicating a good connectivity between the grains together and the size of which is about nm. The nanoparticles were agglomerated from few µm to a few tens of µm. The agglomeration was reduced with increase in grain growth. 4. CONCLUSION Fig. 3: SEM images of CoFe2O4 nanoparticles CoFe 2 O 4 nanoparticles with cubic structure have been successfully synthesized by coprecipitation method. A vibrational spectrum confirms the presence of functional groups in tetrahedral and octahedral complexes, which are indicative of formation of spinel ferrite

5 S. Sathiya, et al., Nano Vision, Vol.5 (4-6), (2015) 137 structure. The prepared crystallites are nearly spherical in shape and their particle sizes are 24nm which is approximately the size calculated by the Debye Scherrer formula. The diffraction analysis clearly confirms the cubic structure of CoFe 2 O 4 nanoparticles and the average particle size of the cobalt ferrite obtained from the peak broadening was 23-29nm, which gives the evidence of formation CoFe 2 O 4 Nanoparticles. ACKNOWLEDGMENT The Corresponding author Dr. K. Parasuraman, would like to express his thanks to the University Grants Commission, South Eastern Region (UGC-SERO), Hyderabad, India, for sanctioning the financial assistance [F. No.6304/15 Dated:] to carry out the present research work. REFERENCES 1. I. H. Gul, A. Maqsood. Structural, magnetic and electrical properties of cobalt ferrites prepared by the sol-gel route. Journal of Alloys and Compounds, 465 (1-2): , (2008). 2. M. Kishimoto, Y. Sakurai, T. Ajima. Magneto optical properties of Ba ferrite particulate media. Journal of Applied Physics, 76 (11): , )1994). 3. S. N. Okuno, S. Hashimoto, K. lnomata. Preferred crystal orientation of cobalt ferrite thin films induced by ion bombardment during deposition. Journal of Applied Physics, 71 (12): , (1992). 4. Juan Yan, Shaobo Mo, Jiaorong Nie, Wenxuan Chen, Xinyu Shen, Jiming Hu, Guangming Haoa and Hua Tong. Colloids and Surfaces A: Physicochem. Eng. Aspects, Coprecipitation synthesis of monodisperse Fe 3 O 4 nanoparticles based on modulation of tartaric acid, 340, (2009). 5. Q. Liu, J. Sun, H. Long, X. Sun, X. Zhong, Z. Xu. Co-precipitation synthesis of CoFe 2 O 4 nanoplatelets and nanoparticles. Materials Chemistry and Physics, 108 (2-3): , (2008). 6. Jacintho GVM, Brolo AG, Corio P, Suarez PAZ, Rubim JC: Structural investigation of MFe 2 O 4 (M = Fe, Co) magnetic fluids. J Phys Chem C, 113: (2009). 7. Xia, A. L., Zhang, H. L. Effects of Excessive Zn2+ Ions on Intrinsic Magnetic and Structural Properties of Ni0.2Zn0.6Cu0.2Fe2O4 Powder Prepared by Chemical Co precipitation. Method Current Applied Physics 10, pp (2010). 8. Lavela, P., Tirado, J. L. CoFe2O4 and NiFe2O4 Synthesized by Sol-gel Procedures for Their Use as Anode Materials for Li Ion Batteries. Journal of Power Sources, 172, pp (2007). 9. Nalbandian, L., Delimitis, A. V., Zaspalis, T., Deliyanni, E. A., Bakoyannakis, D. N., Peleka, E. N. Co-precipitation ly Prepared Nanocrystalline Mn-Zn Ferrites: Synthesis and Characterization Microporous and Mesoporous Materials 114, pp (2008). 10. Barati, M. R., Ebrahimi, S. A. S., Badiei, A. The Role of Surfactant in Synthesis of Magnetic Nanocrystalline Powder of NiFe2O4 by Sol-gel Auto-combustion Method. Journal of Non-Crystalline Solids 354, pp (2008). Nano Vision Vol. 5, Issue 4-6, April-June, 2015 (Pages )

6 138 S. Sathiya, et al., Nano Vision, Vol.5 (4-6), (2015) 11. Gharagozlou, M. Synthesis, Characterization and Influence of Calcinations Temperature on Magnetic Properties of Nanocrystalline Spinel Co-ferrite Prepared by Polymeric Precursor Method. Journal of Alloys and Compounds 486, pp (2009.) 12. Sertkol, M., Koseoglu, Y., Baykal, A., Kavas, H., Toprak, M. S. Synthesis and Magnetic Characterization of Zn0.7Ni0.3Fe2O4 Nanoparticles via Microwave-assisted Combustion Route. Journal of Magnetism and Magnetic Materials 322, pp (2010). 13. Khan, A., Chen, P., Boolchand, P., Smirniotis, P. G. Modified Nano-crystalline Ferrites for High-temperature WGS Membrane Reactor Applications. Journal of Catalysis 253, pp (2008). 14. Hironori Iida, Kosuke Takayannagi, Takkuya Nakamishi, Tetsuya Osaka. Joural of Colloid and Interface Science, 314, (2007). 15. R. Nongjai, S. Khan, K. Asokan, H. Ahmed, I. Khan, J. Appl. Phys. 112, (2012).