Eco-friendly green synthesis and characterizations of CoFe2-x AlxO4 nanocrystals: analysis of structural, magnetic, electrical, and dielectric properties


This work reports, thermal, structural, magnetic, electric, and dielectric investigations of the CoFe2-xAlxO4 nanocrystals synthesized through eco-friendly green sol–gel auto-ignition route. X-ray diffractograms exposed the uni-phasic geometry with Fd3m_\({\text{O}}_{{\text{h}}}^{7}\) space group. The standard crystallite sizes were found in between 24 and 44 nm, confirming the nano-crystalline dimension. FTIR analysis confirmed the two specific vibrational stretching bands corresponding to the spinel ferrite geometry. The surface topology of ferrite nanocrystals with size distribution was effectively observed from TEM micrographs. The magnetic study at room temperature showed lessening in saturation magnetization with rise in Al3+ concentrations, ascribed to the replacement of Fe3+ ions by paramagnetic Al3+ ions. The M–H loops showed the perfect loop of typical soft ferromagnetic behavior of the produced nano-ferrites. The saturation magnetization, coercivity, and magneto-crystalline anisotropy declines with the upsurge in Al3+ ions which is owing to the non-magnetic contamination in the magnetic matrix. The DC-electrical resistivity was enhanced with growing temperature along with Al3+ content x. The dielectric parameters boosted pointedly with Al3+ substitution and decline exponentially with a rise in frequency in compliance with ‘Koops’ phenomenological theory. All the outcomes show that Al3+ substitution influences the physical characteristics of cobalt ferrite nanocrystals which shows its suitability in various technological applications.

Graphic abstract

The graphical abstract presenting the synthesis reaction, TEM micrograph (along with crystallite size distribution) and M–H plots for CoFe2-xAlxO4 nanocrystals.

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  1. 1.

    Torkian, S., Ghasemi, A., Razavi, R.S.: Magnetic properties of hard-soft SrFe10Al2O19/Co0.8Ni0.2Fe2O4 ferrite synthesized by one-pot sol–gel auto-combustion. J. Magn. Magn. Mater. 416, 408–416 (2016)

    Article  CAS  Google Scholar 

  2. 2.

    Batoo, K.M., Kumar, S., Lee, C.G.: Study of ac impedance spectroscopy of Al doped MnFe2−2xAl2xO4. J. Alloys Compd. 480(2), 596–602 (2009)

    Article  CAS  Google Scholar 

  3. 3.

    Sagar, T.V., Rao, T.S., Naidu, K.C.B.: Effect of calcination temperature on optical, magnetic and dielectric properties of sol-gel synthesized Ni0.2Mg0.8-xZnxFe2O4 (x= 0.0–0.8). Ceram. Int. 46, 11515–11529 (2020)

    Article  CAS  Google Scholar 

  4. 4.

    Hashim, M., Kumar, S., Ali, S., Koo, B., Chung, H., Kumar, R.: Structural, magnetic and electrical properties of Al3+ substituted Ni–Zn ferrite nanoparticles. J. Alloys Compd. 511(1), 107–114 (2012)

    Article  CAS  Google Scholar 

  5. 5.

    Karanjkar, M., Tarwal, N., Vaigankar, A., Patil, P.: Structural, Mössbauer and electrical properties of nickel cadmium ferrites. Ceram. Int. 39(2), 1757–1764 (2013)

    Article  CAS  Google Scholar 

  6. 6.

    Kalam, A., Al-Sehemi, A.G., Assiri, M., Du, G., Ahmad, T., Ahmad, I., Pannipara, M.: Modified solvothermal synthesis of cobalt ferrite (CoFe2O4) magnetic nanoparticles photocatalysts for degradation of methylene blue with H2O2/visible light. Results Phys. 8, 1046–1053 (2018)

    Article  Google Scholar 

  7. 7.

    Hannour, A., Vincent, D., Kahlouche, F., Tchangoulian, A., Neveu, S., Dupuis, V.: Self-biased cobalt ferrite nanocomposites for microwave applications. J. Magn. Magn. Mater. 353, 29–33 (2014)

    Article  CAS  Google Scholar 

  8. 8.

    Kharat, P.B., Somvanshi, S.B., Khirade, P.P., Jadhav, K.: Induction heating analysis of surface-functionalized nanoscale CoFe2O4 for magnetic fluid hyperthermia toward noninvasive cancer treatment. ACS Omega 5, 23378–23384 (2020)

    PubMed  PubMed Central  Article  CAS  Google Scholar 

  9. 9.

    Abraham, A.G., Manikandan, A., Manikandan, E., Vadivel, S., Jaganathan, S., Baykal, A., Renganathan, P.S.: Enhanced magneto-optical and photo-catalytic properties of transition metal cobalt (Co2+ ions) doped spinel MgFe2O4 ferrite nanocomposites. J. Magn. Magn. Mater. 452, 380–388 (2018)

    Article  CAS  Google Scholar 

  10. 10.

    Raghavender, A., Kulkarni, R., Jadhav, K.: Magnetic properties of mixed cobalt-aluminum ferrite nanoparticles. Chin. J. Phys. 48(4), 512–522 (2010)

    CAS  Google Scholar 

  11. 11.

    Chauhan, C.C., Jotania, R.B., Sandhu, C.S.: Structural, magnetic and dielectric properties of aluminum cobalt substituted M−type strontium hexaferrites. Magn. Oxides Compos. 31, 216 (2018)

    Article  CAS  Google Scholar 

  12. 12.

    Alshehri, S.M., Ahmed, J., Alhabarah, A.N., Ahamad, T., Ahmad, T.: Nitrogen-doped cobalt ferrite/carbon nanocomposites for supercapacitor applications. ChemElectroChem 4(11), 2952–2958 (2017)

    Article  CAS  Google Scholar 

  13. 13.

    Ansari, S., Arabi, H., Sadr, S.M.A.: Structural, morphological, optical and magnetic properties of Al-doped CoFe2O4 nanoparticles prepared by sol-gel auto-combustion method. J. Supercond. Nov. Magn. 29(6), 1525–1532 (2016)

    Article  CAS  Google Scholar 

  14. 14.

    Bitar, Z., Abdeen, W., Awad, R.: Effect of Er3+ and Pr3+ on the structural, magnetic and dielectric properties of Zn-Co ferrite synthesised via co-precipitation method. Mater. Res. Innov. 24(2), 104–112 (2020)

    Article  CAS  Google Scholar 

  15. 15.

    Houshiar, M., Zebhi, F., Razi, Z.J., Alidoust, A., Askari, Z.: Synthesis of cobalt ferrite (CoFe2O4) nanoparticles using combustion, coprecipitation, and precipitation methods: A comparison study of size, structural, and magnetic properties. J. Magn. Magn. Mater. 371, 43–48 (2014)

    Article  CAS  Google Scholar 

  16. 16.

    Kurtan, U., Topkaya, R., Baykal, A., Toprak, M.: Temperature dependent magnetic properties of CoFe2O4/CTAB nanocomposite synthesized by sol–gel auto-combustion technique. Ceram. Int. 39(6), 6551–6558 (2013)

    Article  CAS  Google Scholar 

  17. 17.

    Shamaila, S., Sajjad, A.K.L., Farooqi, S.A., Jabeen, N., Majeed, S., Farooq, I.: Advancements in nanoparticle fabrication by hazard free eco-friendly green routes. Appl. Mater. Today 5, 150–199 (2016)

    Article  Google Scholar 

  18. 18.

    Ahmad, T., Phul, R., Khatoon, N., Sardar, M.: Antibacterial efficacy of Ocimum sanctum leaf extract-treated iron oxide nanoparticles. New J. Chem. 41(5), 2055–2061 (2017)

    Article  CAS  Google Scholar 

  19. 19.

    Naik, M.M., Naik, H.B., Nagaraju, G., Vinuth, M., Vinu, K., Viswanath, R.: Green synthesis of zinc doped cobalt ferrite nanoparticles: Structural, optical, photocatalytic and antibacterial studies. Nano-Struct. Nano-Objects 19, 100322 (2019)

    Article  CAS  Google Scholar 

  20. 20.

    Yadav, R.S., Kuřitka, I., Vilcakova, J., Havlica, J., Masilko, J., Kalina, L., Tkacz, J., Enev, V., Hajdúchová, M.: Structural, magnetic, dielectric, and electrical properties of NiFe2O4 spinel ferrite nanoparticles prepared by honey-mediated sol-gel combustion. J. Phys. Chem. Solids 107, 150–161 (2017)

    Article  CAS  Google Scholar 

  21. 21.

    Kumar, S., Sharma, A., Singh, M., Sharma, S.P.: Simple synthesis and magnetic properties of nickel-zinc ferrites nanoparticles by using Aloe vera extract solution. Arch. Appl. Sci. Res. 5(6), 145–151 (2013)

    CAS  Google Scholar 

  22. 22.

    Patil, S., Naik, H.B., Nagaraju, G., Viswanath, R., Rashmi, S.K.: Sugarcane juice mediated eco-friendly synthesis of visible light active zinc ferrite nanoparticles: Application to degradation of mixed dyes and antibacterial activities. Mater. Chem. Phys. 212, 351–362 (2018)

    Article  CAS  Google Scholar 

  23. 23.

    Amiri, M., Salavati-Niasari, M., Pardakhty, A., Ahmadi, M., Akbari, A.: Caffeine: A novel green precursor for synthesis of magnetic CoFe2O4 nanoparticles and pH-sensitive magnetic alginate beads for drug delivery. Mater. Sci. Eng. C 76, 1085–1093 (2017)

    Article  CAS  Google Scholar 

  24. 24.

    Muniz, E., Proveti, J., Pereira, R., Segatto, B., Porto, P., Nascimento, V., Schettino, M., Passamani, E.C.: Influence of heat-treatment environment on Ni-ferrite nanoparticle formation from coconut water precursor. J. Mater. Sci. 48(4), 1543–1554 (2013)

    Article  CAS  Google Scholar 

  25. 25.

    Kombaiah, K., Vijaya, J.J., Kennedy, L.J., Bououdina, M.: Studies on the microwave assisted and conventional combustion synthesis of Hibiscus rosa-sinensis plant extract based ZnFe2O4 nanoparticles and their optical and magnetic properties. Ceram. Int. 42(2), 2741–2749 (2016)

    Article  CAS  Google Scholar 

  26. 26.

    Tiwari, P., Verma, R., Kane, S., Tatarchuk, T., Mazaleyrat, F.: Effect of Zn addition on structural, magnetic properties and anti-structural modeling of magnesium-nickel nano ferrites. Mater. Chem. Phys. 229, 78–86 (2019)

    Article  CAS  Google Scholar 

  27. 27.

    Lassoued, A., Lassoued, M.S., Dkhil, B., Ammar, S., Gadri, A.: Substituted effect of Al3+ on structural, optical, magnetic and photocatalytic activity of Ni ferrites. J. Magn. Magn. Mater. 476, 124–133 (2019)

    Article  CAS  Google Scholar 

  28. 28.

    Raut, A., Khirade, P., Humbe, A., Jadhav, S., Shengule, D.: Structural, electrical, dielectric and magnetic properties of Al3+ substituted Ni-Zn ferrite. J. Supercond. Nov. Magn. 29(5), 1331–1337 (2016)

    Article  CAS  Google Scholar 

  29. 29.

    Srinivasamurthy, K., Kubrin, S., Matteppanavar, S., Sarychev, D., Kumar, P.M., Azale, H.W., Rudraswamy, B.: Tuning of ferrimagnetic nature and hyperfine interaction of Ni2+ doped cobalt ferrite nanoparticles for power transformer applications. Ceram. Int. 44(8), 9194–9203 (2018)

    Article  CAS  Google Scholar 

  30. 30.

    Dipesh, D.N., Wang, L., Adhikari, H., Alam, J., Mishra, S.: Influence of Al3+ doping on structural and magnetic properties of CoFe2-xAlxO4 Ferrite nanoparticles. J. Alloys Compd. 688, 413–421 (2016)

    Article  CAS  Google Scholar 

  31. 31.

    Kumar, L., Kumar, P., Kar, M.: Effect of non-magnetic substitution on the structural and magnetic properties of spinel cobalt ferrite (CoFe2−xAlxO4) ceramics. J. Mater. Sci. 24(8), 2706–2715 (2013)

    CAS  Google Scholar 

  32. 32.

    Bromho, T.K., Ibrahim, K., Kabir, H., Rahman, M.M., Hasan, K., Ferdous, T., Taha, H., Altarawneh, M., Jiang, Z.-T.: Understanding the impacts of Al+3-substitutions on the enhancement of magnetic, dielectric and electrical behaviors of ceramic processed nickel-zinc mixed ferrites: FTIR assisted studies. Mater. Res. Bull. 97, 444–451 (2018)

    Article  CAS  Google Scholar 

  33. 33.

    Naik, M.M., Naik, H.B., Nagaraju, G., Vinuth, M., Vinu, K., Rashmi, S.: Effect of aluminium doping on structural, optical, photocatalytic and antibacterial activity on nickel ferrite nanoparticles by sol–gel auto-combustion method. J. Mater. Sci. 29(23), 20395–20414 (2018)

    CAS  Google Scholar 

  34. 34.

    Chavan, A.R., Birajdar, S.D., Chilwar, R.R., Jadhav, K.: Structural, morphological, optical, magnetic and electrical properties of Al3+ substituted nickel ferrite thin films. J. Alloys Compd. 735, 2287–2297 (2018)

    Article  CAS  Google Scholar 

  35. 35.

    Pourgolmohammad, B., Masoudpanah, S., Aboutalebi, M.: Effect of starting solution acidity on the characteristics of CoFe2O4 powders prepared by solution combustion synthesis. J. Magn. Magn. Mater. 424, 352–358 (2017)

    Article  CAS  Google Scholar 

  36. 36.

    Gabriel Cozma, D., Gherca, D., Mihalcea, I., Virlan, C., Cornei, N., Pui, A.: Correlation between size of CoFe2O4 nanoparticles determined from experimental and calculated data by different mathematical models. Curr. Nanosci. 10(6), 869–876 (2014)

    Article  CAS  Google Scholar 

  37. 37.

    Nethala, G.P., Tadi, R., Gajula, G.R., Madduri, P.P., Anupama, A., Veeraiah, V.: Influence of Cr on structural, spectroscopic and magnetic properties of CoFe2O4 grown by the wet chemical method. Mater. Chem. Phys. 238, 121903 (2019)

    Article  CAS  Google Scholar 

  38. 38.

    Xi, L., Wang, Z., Zuo, Y., Shi, X.: The enhanced microwave absorption property of CoFe2O4 nanoparticles coated with a Co3Fe7–Co nanoshell by thermal reduction. Nanotechnology 22(4), 045707 (2010)

    PubMed  Article  CAS  PubMed Central  Google Scholar 

  39. 39.

    Chavan, A.R., Kounsalye, J.S., Chilwar, R.R., Kale, S.B., Jadhav, K.: Cu2+ substituted NiFe2O4 thin films via spray pyrolysis technique and their high-frequency devices application. J. Alloys Compd. 769, 1132–1145 (2018)

    Article  CAS  Google Scholar 

  40. 40.

    Khirade, P.P., Birajdar, S.D., Shinde, A., Jadhav, K.M.: Room temperature ferromagnetism and photoluminescence of multifunctional Fe doped BaZrO3 nanoceramics. J. Alloys Compd. 691, 287–298 (2017)

    Article  CAS  Google Scholar 

  41. 41.

    Khirade, P.P., Birajdar, S.D., Humbe, A.V., Jadhav, K.M.: Structural, electrical and dielectrical property investigations of Fe-doped BaZrO3 nanoceramics. J. Electron. Mater. 45(6), 3227–3235 (2016)

    Article  CAS  Google Scholar 

  42. 42.

    Toksha, B., Shirsath, S.E., Mane, M., Jadhav, K.: Auto-ignition synthesis of CoFe2O4 with Al3+ substitution for high frequency applications. Ceram. Int. 43(16), 14347–14353 (2017)

    Article  CAS  Google Scholar 

  43. 43.

    Waghmare, S., Borikar, D., Rewatkar, K.: Impact of Al doping on structural and magnetic properties of Co-ferrite. Mater. Today: Proc. 4(11), 11866–11872 (2017)

    Google Scholar 

  44. 44.

    Khirade, P.P., Shinde, A., Raut, A., Birajdar, S.D., Jadhav, K.M.: Investigations on the synthesis, structural and microstructural characterizations of Ba1-xSrxZrO3 nanoceramics. Ferroelectrics 504(1), 216–229 (2016)

    Article  CAS  Google Scholar 

  45. 45.

    Kadam, A., Shinde, S., Yadav, S., Patil, P., Rajpure, K.: Structural, morphological, electrical and magnetic properties of Dy doped Ni–Co substitutional spinel ferrite. J. Magn. Magn. Mater. 329, 59–64 (2013)

    Article  CAS  Google Scholar 

  46. 46.

    Chavan, A.R., Babrekar, M., Nawle, A.C., Jadhav, K.: Impact of trivalent metal ion doping on structural, photoluminescence and electric properties of NiFe2O4 thin films. J. Electron. Mater. 48(8), 5184–5194 (2019)

    Article  CAS  Google Scholar 

  47. 47.

    Priya, A.S., Geetha, D., Kavitha, N.: Effect of Al substitution on the structural, electric and impedance behavior of cobalt ferrite. Vacuum 160, 453–460 (2019)

    Article  CAS  Google Scholar 

  48. 48.

    Vinayak, V., Khirade, P.P., Birajdar, S.D., Sable, D., Jadhav, K.M.: Structural, microstructural, and magnetic studies on magnesium (Mg2+)-substituted CoFe2O4 nanoparticles. J. Supercond. Nov. Magn. 29(4), 1025–1032 (2016)

    Article  CAS  Google Scholar 

  49. 49.

    Vlazan, P., Miron, I., Sfirloaga, P.: Cobalt ferrite substituted with Mn: synthesis method, characterization and magnetic properties. Ceram. Int. 41(3), 3760–3765 (2015)

    Article  CAS  Google Scholar 

  50. 50.

    Ghasemi, A., Ekhlasi, S., Mousavinia, M.: Effect of Cr and Al substitution cations on the structural and magnetic properties of Ni0.6Zn0.4Fe2−xCrx/2Alx/2O4 nanoparticles synthesized using the sol–gel auto-combustion method. J. Magn. Magn. Mater. 354, 136–145 (2014)

    Article  CAS  Google Scholar 

  51. 51.

    Aghav, P., Dhage, V.N., Mane, M.L., Shengule, D., Dorik, R., Jadhav, K.M.: Effect of aluminum substitution on the structural and magnetic properties of cobalt ferrite synthesized by sol–gel auto combustion process. Physica B Condens. 406(23), 4350–4354 (2011)

    Article  CAS  Google Scholar 

  52. 52.

    Chilwar, R.R., Chavan, A.R., Babrekar, M., Jadhav, K.M.: Impact of trivalent metal ion substitution on structural, optical, magnetic and dielectric properties of Li0.5Fe2.5O4 thin films. Physica B Condens. 566, 43–49 (2019)

    Article  CAS  Google Scholar 

  53. 53.

    Khirade, P.P.: Structural, microstructural and magnetic properties of sol–gel-synthesized novel BaZrO3–CoFe2O4 nanocomposite. J. Nanostructure Chem. 9(3), 163–173 (2019)

    Article  CAS  Google Scholar 

  54. 54.

    Chavan, A.R., Shisode, M.V., Undre, P.G., Jadhav, K.: Influence of Cr3+ substitution on structural, morphological, optical, and magnetic properties of nickel ferrite thin films. Appl. Phys. A 125(7), 472 (2019)

    Article  CAS  Google Scholar 

  55. 55.

    Bharathi, K.K., Chelvane, J.A., Markandeyulu, G.: Magnetoelectric properties of Gd and Nd-doped nickel ferrite. J. Magn. Magn. Mater. 321(22), 3677–3680 (2009)

    Article  CAS  Google Scholar 

  56. 56.

    Khirade, P.P., Birajdar, S.D., Raut, A., Jadhav, K.M.: Effect of Fe–substitution on phase transformation, optical, electrical and dielectrical properties of BaTiO3 nanoceramics synthesized by sol-gel auto combustion method. J. Electroceram. 37(1–4), 110–120 (2016)

    Article  CAS  Google Scholar 

  57. 57.

    Raju, K., Balaji, C., Reddy, P.V.: Microwave properties of Al and Mn doped nickel ferrites at Ku band frequencies. J. Magn. Magn. Mater. 354, 383–387 (2014)

    Article  CAS  Google Scholar 

  58. 58.

    Kumar, G., Chand, J., Dogra, A., Kotnala, R., Singh, M.: Improvement in electrical and magnetic properties of mixed Mg–Al–Mn ferrite system synthesized by citrate precursor technique. J. Phys. Chem. Solids 71(3), 375–380 (2010)

    Article  CAS  Google Scholar 

  59. 59.

    Ahmad, T., Lone, I.H.: Development of multifunctional lutetium ferrite nanoparticles: Structural characterization and properties. Mater. Chem. Phys. 202, 50–55 (2017)

    Article  CAS  Google Scholar 

  60. 60.

    Sontu, U.B., Yelasani, V., Musugu, V.R.R.: Structural, electrical and magnetic characteristics of nickel substituted cobalt ferrite nano particles, synthesized by self combustion method. J. Magn. Magn. Mater. 374, 376–380 (2015)

    Article  CAS  Google Scholar 

  61. 61.

    Chavan, A.R., Somvanshi, S.B., Khirade, P.P., Jadhav, K.: Influence of trivalent Cr ion substitution on the physicochemical, optical, electrical, and dielectric properties of sprayed NiFe 2 O 4 spinel-magnetic thin films. RSC Adv. 10(42), 25143–25154 (2020)

    Article  CAS  Google Scholar 

  62. 62.

    George, M., Nair, S.S., Malini, K., Joy, P., Anantharaman, M.: Finite size effects on the electrical properties of sol–gel synthesized CoFe2O4 powders: Deviation from Maxwell-Wagner theory and evidence of surface polarization effects. J. Phys. D Appl. Phys. 40(6), 1593 (2007)

    Article  CAS  Google Scholar 

  63. 63.

    Vinayak, V., Khirade, P.P., Birajdar, S.D., Alange, R., Jadhav, K.M.: Electrical and dielectrical properties of low-temperature-synthesized nanocrystalline Mg2+-substituted cobalt spinel ferrite. J. Supercond. Nov. Magn. 28(11), 3351–3356 (2015)

    Article  CAS  Google Scholar 

  64. 64.

    Dar, M.A., Batoo, K.M., Verma, V., Siddiqui, W., Kotnala, R.: Synthesis and characterization of nano-sized pure and Al-doped lithium ferrite having high value of dielectric constant. J. Alloys Compd. 493(1–2), 553–560 (2010)

    Article  CAS  Google Scholar 

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One of the authors (Dr. Apparao R. Chavan) is thankful to the Punyashlok Ahilyadevi Holkar University, Solapur, IIT Madras, and IIT Kanpur for providing XRD, VSM, and TEM characterization facilities.

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ARC: Formal analysis, investigation, methodology, data curation, visualization, writing original draft. PKD: Conceptualization, investigation, methodology, writing-review & editing. SBS: Formal analysis, visualization. SVM: Data curation, validation. KMJ: Supervision.

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Correspondence to Apparao R. Chavan or Pankaj P. Khirade.

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Chavan, A.R., Khirade, P.P., Somvanshi, S.B. et al. Eco-friendly green synthesis and characterizations of CoFe2-x AlxO4 nanocrystals: analysis of structural, magnetic, electrical, and dielectric properties. J Nanostruct Chem (2021).

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  • Green synthesis
  • Spinel ferrite
  • Structural
  • Magnetic
  • Electric properties