Mixed Mg-Cr Nano ferrites having the compositional formula MgCrxFe2-xO4 (where x=0.0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0) were synthesized using Citrate-Gel auto combustion method. Structural characterization was carried out by XRD Analysis which confirmed the formation of single phase cubic spinel structure without any impurity peak. The dielectric properties such as Dielectric constant (ε'), Dielectric Loss tangent (tanδ) and AC conductivity (σAC) of Mg-Cr nano ferrites were studied at room temperature in the frequency range of 2Hz - 2MHz using Agilent E4980A Precision LCR meter.The dielectric constant, loss tangent and AC conductivity shows a normal behavior with frequency. A qulitative explanation is given for composition and frequency dependance of the dielectric constant, dielectric loss tangent and AC conductivity of the nano ferrite. The loss tangent for the synthesized samples was found to be decreased from 0.09 to 0.054 in higher frequency region showing the potential applications of these materials in high frequency micro wave devices. On the basis of these results the explanation of dielectric mechanism in Mg-Cr ferrites is suggested.
Cite this paper
M. Raghasudha, D. Ravinder and P. Veerasomaiah, "Influence of Cr3+ Ion on the Dielectric Properties of Nano Crystalline Mg-Ferrites Synthesized by Citrate-Gel Method," Materials Sciences and Applications, Vol. 4 No. 7, 2013, pp. 432-438. doi: 10.4236/msa.2013.47052.
 Y. Yamamoto and J. Makino, “Core Losses and Magnetic Properties of Mn-Zn Ferrites with Fine Grain Sizes,” Journal of Magnetism and Magnetic Materials, Vol. 133, No. 1-3, 1994, pp. 500-503.
 J. Smit and H. P. G. Wijn, “Ferrites,” John and Wiley & Sons, Inc., Hoboken, 1959, p. 136.
 M. Sugimoto, “The Past, Present, and Future of Ferrites,” Journal of Ceramic American Society, Vol. 82, No. 2, 1999, p. 269.
 K. Kondo, T. Chiba and S. Yamada, “Effect of Microstructure on Magnetic Properties of Ni-Zn Ferrites,” Journal of Magnetism and Magnetic Materials, Vol. 541, 2003, p. 254.
 M. P. Reddy, G. Balakrishnaiah, W. Madhuri, M. Venkata Ramana, N. Rammanohar Reddy, K. V. Siva Kumar, V. R. K. Murthy and R. Ramakrishna Reddy, “Structural, Magnetic and Electrical Properties of NiCuZn Ferrites Prepared by Microwave Sintering Method Suitable for MLCI Applications,” Journal of Physis and Chemistry of Solids, Vol. 71, 2010, p. 1373.
 L. B. Kong, Z. W. Li, G. Q. Lin and Y. B. Gan, “Magneto-Dielectric Properties of Mg-Cu-Co Ferrite Ceramics: II. Electrical, Dielectric, and Magnetic Properties,” Journal of American Ceramic Society, Vol. 90, 2007, p. 2014.
 Y. Konseoglu, H. Kavas and B. Aktas, “Surface Effects on Magnetic Properties of Superparamagnetic Magnetite Nanoparticles,” Physics Status Solidi A, Vol. 203, 2006, p. 1595. doi:10.1002/pssa.200563104
 S. L. Gupta and S. Gupta, “Electricity, Magnetism and Electronics,” Vol. 1, Jaiprakash Nath and Company, 1991, p. 60.
 E. Pervaiz and I. H. Gul, “Enhancement of Electrical Properties Due to Cr+3 Substitution in Co-Ferrite Nano Particles Synthesized by Two Chemical Techniques,” Journal of Magnetism and Magnetic Materials, Vol. 324, No. 22, 2012, pp. 3695-3703.
 B. D. Cullity, “Elements of XRD,” Addison Weseley Publishing, Redading, 1959, p. 132.
 M. J. Iqbal, M. N. Ashiq, P. Hernandez-Gomezb and J. M. Munoz, “Synthesis, Physical, Magnetic and Electrical Properties of Al-Ga Substituted Co-Precipitated Nanocrystalline Strontium Hexaferrite,” Journal of Magnetism and Magnetic Materials, Vol. 320, 2007, No. 6, pp. 881-886.
 B. Chandra Babu, V. Naresh, B. Jayaprakash and S. Buddhudu, “Structural, Thermal and Dielectric Properties of Lithium Zinc Silicate Ceramic Powders by Sol-Gel Method,” Ferro Electrics Letter, Vol. 38, 2011, p. 124.
 S. Sindhu, M. R. Antharaman, B. P. Thampi, K. A. Malini and Ph. Kurian, “Tailoring Magnetic and Dielectric Properties of Rubber Ferrite Composites Containing Mixed Ferrites,” Bulletin Materials Science, Vol. 24, 2001, pp. 623-629. doi.10.1007/BF02704011
 A. A. Zaky and R. Hawley, “Dielectric Solids,” Routledge and Kegan Paul Ltd., London, 1990, p. 21
 N. Rezlescu and E. Rezlescu, Physics Status Solidi A, Vol. 23, 1974, p. 575
 I. H. Gul, A. Maqsood, M. Naeem and M. Naeem Ashiq, “Optical, Magnetic and Electrical Investigation of Cobalt Ferrite Nanoparticles Synthesized by Co-Precipitation Route,” Journal of Alloys and Compounds, Vol. 507, No. 1, 2010, pp. 201-206. doi.10.1016/j.jallcom.2010.07.155
 J. C. Maxwell, “Electricity and Magnetism,” Vol. 1, Oxford University Press, Oxford, 1929.
 K. W. Wagner, “Zur Theorie der Unvolkommenen DiElektrika,” American Physics, American Physics, Vol. 40, 1913, p. 817.
 I. T. Rabinkin and Z. I. Novikova, “Ferrites,” IZV Acad. Nauk USSR Minsk, 1960.
 B. Baruwati, K. M. Reddy, V. Sunkara, R. K. Manorama, O. Singh and J. Prakash, “Tailored Conductivity Behavior in Nanocrystalline Nickel Ferrite,” Applied Physics Letters, Vol. 85, No. 14, 2004. doi.10.1063/1.1801685
 R. S. Devan and B. K. Chougule, “Effect of Composition on Coupled Electric Magnetic and Dielectric Properties of Two Phase Particulate Magnetoelectric Composite,” Journal of Applied Physics, Vol. 101, No. 1, 2007, Article ID: 014109
 C. G. Koops, Physics Revision, “On the Dispersion of Resistivity and Dielectric Constant of Some Semiconductors at Audiofrequencies,” Vol. 83, No. 1, 1951, pp. 121124. doi.10.1103/PhysRev.83.121
 D. Alder and J. Fienleib, “Electrical and Optical Properties of Narrow-Band Materials,” Physics Revision B, Vol. 2, 1970, p. 3112. doi.10.1103/PhysRevB.2.3112
 D. Elkony, “Egypt,” Journal of Solids, Vol. 27, No. 2, 2004, p. 285.
 S. E. Shirsath, B. G. Toksh, M. K. L. Mane, V. N. Dhage, D. R. Shengule and K. M. Jadhav, “Frequency, Temperature and In+3 Dependent Electrical Conduction in NiFe2O4 Powder,” Powder Technology, Vol. 212, No. 1, 2011, pp. 218-223. doi.10.1016/j.powtec.2011.05.019