Journal of the Korean Chemical Society (대한화학회지)

Korean Chemical Society (대한화학회)
권호 표지
DOI QR코드

DOI QR Code

Sol-Gel Synthesis, Crystal Structure, Magnetic and Optical Properties in ZnCo2O3 Oxide

  • Das, Bidhu Bhusan (Department of Chemistry, Functional Materials Chemistry Laboratory, Pondicherry University) ;
  • Barman, Bittesh (Department of Chemistry, Functional Materials Chemistry Laboratory, Pondicherry University)
  • Received : 2019.05.05
  • Accepted : 2019.08.13
  • Published : 2019.12.20
Download PDF
⟨ Previous Next ⟩

Abstract

Synthesis of ZnCo2O3 oxide is performed by sol-gel method via nitrate-citrate route. Powder X-ray diffraction (XRD) study shows monoclinic unit cell having lattice parameters: a = 5.721(1) Å, b = 8.073(2) Å, c = 5.670(1) Å, β = 93.221(8)°, space group P2/m and Z = 4. Average crystallite sizes determined by Scherrer equation are the range ~14-32 nm, whereas SEM micrographs show nano-micro meter size particles formed in ZnCo2O3. Endothermic peak at ~798 K in the Differential scanning calorimetric (DSC) trace without weight loss could be due to structural transformation and the endothermic peak ~1143 K with weight loss is due to reversible loss of O2 in air atmosphere. Energy Dispersive X-ray (EDX) analysis profile shows the presence of elements Zn, Co and O which indicates the purity of the sample. Magnetic measurements in the range of +12 kOe to -12 kOe at 10 K, 77 K, 120 K and at 300 K by PPMS-II Physical Property Measurement System (PPMS) shows hysteresis loops having very low values of the coercivity and retentivity which indicates the weakly ferromagnetic nature of the oxide. Observed X-band EPR isotropic lineshapes at 300 K and 77 K show positive g-shift at giso ~2.230 and giso ~2.217, respectively which is in agreement with the presence of paramagnetic site Co2+(3d7) in the oxide. DC conductivity value of 2.875 ×10-8 S/cm indicates very weakly semiconducting nature of ZnCo2O3 at 300 K. DRS absorption bands ~357 nm, ~572 nm, ~619 nm and ~654 nm are due to the d-d transitions 4T1g(4F)→2Eg(2G), 4T1g(4F)→4T1g(4P), 4T1g(4F)→4A2g(4F), 4T1g(4F)→4T2g(4F), respectively in octahedral ligand field around Co2+ ions. Direct band gap energy, Eg~ 1.5 eV in the oxide is obtained by extrapolating the linear part of the Tauc plot to the energy axis indicates fairly strong semiconducting nature of ZnCo2O3.

Keywords

References

  1. Duan, X. F.; Huang, Y.; Agarwal, R.; Lieber, C. M. Nature 2003, 421, 241. https://doi.org/10.1038/nature01353
  2. Gudiksen, M.S.; Lauhon, L. J.; Wang J. F.; Smith, D. C.; Lieber, C. M. Nature 2002, 415, 617. https://doi.org/10.1038/415617a
  3. Hgfeldt, A.; Gratzel, M. Chem. Rev. 1995, 95, 49. https://doi.org/10.1021/cr00033a003
  4. Duan, X. F.; Huang, Y.; Cui, Y.; Wang, J. F.; Lieber, C.M. Nature 2001, 409, 66. https://doi.org/10.1038/35051047
  5. Hu, J. G,; Odom, T. W.; Lieber, C.M. Acc. Chem. Res. 1999, 32, 435. https://doi.org/10.1021/ar9700365
  6. Yao, Z.; Postma, H. W. C.; Balents, L.; Dekker, C. Nature 1999, 402, 273. https://doi.org/10.1038/46241
  7. Yang, P.; Lieber, C. M. Science 1996, 273, 1836. https://doi.org/10.1126/science.273.5283.1836
  8. Gowrishankar, M.; Babu, D. R.; Madeswaran, S. J. Magn. Magn. Mater. 2016, 418, 54. https://doi.org/10.1016/j.jmmm.2016.03.085
  9. Ramesh, S.; Ramaclus, J. V.; Mosquera, E.; Das, B. B. RSC Adv. 2016, 6, 6336. https://doi.org/10.1039/C5RA24925B
  10. Wei, W.; Cui, X.; Chen, W.; Ivey, D. G. Chem. Soc. Rev. 2011, 40, 1697. https://doi.org/10.1039/C0CS00127A
  11. Choi, C. H.; Park, S. H.; Woo, S. I. Phys. Chem. Chem. Phys. 2012, 14, 6842. https://doi.org/10.1039/c2cp24128e
  12. Ganguly, A.; Anjaneyulu, O.; Ojha, K.; Ganguli, A. K. Cryst. Eng. Comm. 2015, 17, 8978. https://doi.org/10.1039/C5CE01343G
  13. Mao, Y.; Park, T. J.; Wong, S. S. Chem Commun. 2005, 46, 5721. https://doi.org/10.1039/b509960a
  14. Gulden, C.; Suleyman, C. Cent. Eur. J. Phys. 2013, 11, 387.
  15. Ohkoshi, S.; Tsunobuchi, Y.; Matsuda, T.; Hashimoto, K.; Namai, A.; Hakoe, F.; Tokoro, H. Nat. Chem. 2010, 2, 539. https://doi.org/10.1038/nchem.670
  16. Sevincli, H.; Topsakal, M.; Durgun, E.; Ciraci, S. Phys. Rev. B 2008, 77, 195434. https://doi.org/10.1103/physrevb.77.195434
  17. Osaka, T.; Sayama, J. Electrochim. Acta 2007, 52, 2884. https://doi.org/10.1016/j.electacta.2006.09.005
  18. Sun, L.; Zhang, R.; Wang, Z.; Ju, L.; Cao, E.; Zhang, Y. J. Magn. Magn. Mater. 2017, 421, 65. https://doi.org/10.1016/j.jmmm.2016.08.003
  19. Das, B. B.; Ramesh, S. AIP Conf. Proc. 2008, 1003, 85.
  20. Opuchovic, O.; Kareiva, A.; Mazeika, K.; Baltrunas, D. J. Magn. Magn. Mater. 2017, 442, 425. https://doi.org/10.1016/j.jmmm.2016.09.041
  21. Yue, Z.; Li, L.; Zhou, J.; Zhang, H.; Gui, Z. Mater. Sci. Eng. 1999, B 4, 69.
  22. Epifani, M.; Melissano, E.; Pace, G.; Schioppa, M. J. Eur. Ceram Soc. 2007, 27, 115. https://doi.org/10.1016/j.jeurceramsoc.2006.04.084
  23. Roisnel, T.; Carvajal, J.R. Mater. Sci. Forum 2001, 378, 118. https://doi.org/10.4028/www.scientific.net/MSF.378-381.118
  24. Patterson, A. L. Phys. Rev. 1939, 56, 978. https://doi.org/10.1103/PhysRev.56.978
  25. Jayswal, M. S.; Kanchan, D. K.; Sharma, P.; Gondaliya, N. Mater. Sci. Eng. B 2013, 178, 775. https://doi.org/10.1016/j.mseb.2013.03.013
  26. Das, B. B.; Rao, R. G. Phys. Status Solidi B 2015, 252, 2680. https://doi.org/10.1002/pssb.201451753
  27. Ballhausen, C. J. Introduction to Ligand Field Theory; McGraw Hill Book Company Inc.: New York, 1966; p 258.
  28. Figgis, B. N. Introduction to Ligand Fields, 1st ed. Wiley Eastern Limited: New Delhi, 1976; p 21.
  29. Tauc, J.; Grigorovici, R.; Vancu, A. Phys. Status Solidi B 1966, 15, 627. https://doi.org/10.1002/pssb.19660150224