Magnetic Phase Separation in Diluted Magnetic System: Zn1-xFexO

doi:10.1007/s40195-017-0530-6

Abstract

Abstract:

Single-phase diluted magnetic systems Zn_1-_xFe_xO have been prepared by chemical route. Structural and spectroscopic (UV-Vis and M?ssbauer) studies indicate the incorporation of Fe³⁺ ions in the lattice sites. The UV-Vis results point to a systematic increase in the band gap with increasing Fe doping. The room temperature magnetization of Zn_1-_xFe_xO indicates a paramagnetic behavior which is in accordance with the M?ssbauer results, illustrating quadrupolar doublet. At low temperature, the zero-field-cooled (ZFC) magnetization shows a cusp and this temperature increases systematically with decreasing particle size. The weak exchange bias effect manifested by a M-H loop shift is observed for x = 0.03. This shift is accompanied by the enhancement of coercivity. The dc magnetization results suggest the coexistence of ferromagnetic and antiferromagnetic exchange interactions for low doping of Fe, i.e., for x = 0.03.

Key words: Diluted magnetic system, Optical band gap, Mo¨, ssbauer, Exchange bias effect

Archita Mondal, Sanchari Sarkar, Neepamala Giri, Souvik Chatterjee, Ruma Ray. Magnetic Phase Separation in Diluted Magnetic System: Zn_1-_xFe_xO[J]. Acta Metallurgica Sinica (English Letters), 2017, 30(6): 521-527.

Figures/Tables 6

Fig. 1 a XRD patterns of Zn1-xFexO (where 0.0 ≤ x ≤ 0.13) nanoparticles. b Rietveld refinements for Zn1-xFexO with x = 0.03 and 0.13. c Unit cell parameter of Zn1-xFexO nanoparticles (where 0.0 ≤ x ≤ 0.13) as a function of Fe doping (x). Inset shows the variation of c/a with x. d Peak position of Zn1-xFexO (101) XRD line with 0.0 ≤ x ≤ 0.13. Inset shows the shifting of XRD line with x. e Variation of the particle size of Zn1-xFexO (0.0 ≤ x ≤ 0.13) nanoparticles, obtained from Williamson-Hall plot with x

Fig. 2 FE-SEM image of Zn1-xFexO nanoparticles where x = 0.13. Inset shows the particle size distribution following Lorentz distribution shown by continuous fitted line

Fig. 3 Plot of (αhν)2 versus hν of Zn1-xFexO nanoparticles where 0.0 ≤ x ≤ 0.13. Inset shows the variation of band gap with x

Fig. 4 M?ssbaurer spectra of Zn1-xFexO nanoparticles (0.0 < x ≤ 0.13) at 300 K. The solid lines indicate the satisfactory fits. Right inset confirms the absence of magnetic hyperfine split sextet pattern at 300 K. Left inset shows the variation of quadrupolar splitting (QS) and isomer shift (IS) with x

Fig. 5 EPR spectra of Zn1-xFexO nanoparticles (0.0 < x ≤ 0.13) at 300 K. Inset shows the variation of line width (ΔHpp) with x

Fig. 6 a Temperature variation of ZFC and FC magnetization of Zn1-xFexO nanoparticles (with x = 0.03, 0.06 and 0.09) measured at 100 Oe. Upper inset highlights the cusp position TP for different x. Lower inset shows a systematic variation of TP with the particle size. b Magnetic hysteresis loop of Zn1-xFexO nanoparticles (with x = 0.03, 0.06 and 0.09) measured at 300 K. c Magnetic hysteresis loop of Zn1-xFexO nanoparticles (with x = 0.03, 0.06 and 0.09) measured at 2 K. Inset shows the variation of magnetic moment per Fe atom, measured at 5 T and 2 K, with x. d Hysteresis loop of Zn1-xFexO nanoparticles (with x = 0.03) measured in FC mode under different cooling field at 5 K. Bottom right inset highlights the central portion of M-H loop indicating exchange bias effect. Top left inset shows the variation of coercivity with cooling field (Hcool)

References

[1]	M. Bouloudenine, N. Viart, S. Colis, J. Kortus, A. Dinia, Appl. Phys. Lett. 87, 052501(2005)
[2]	Y.M. Kin, M. Yoon, I.W. Park, J.H. Lyou, Solid State Commun. 129, 175(2004)
[3]	Marcel H. Phys. Rev. Lett. 94, 187204(2005)
[4]	J.M.D. Nat. Mater. 4, 173(2005)
[5]	D. Karmakar, S.K. Mandal, R.M. Kadam, P.L. Paulose, A.K. Rajarajan, T.K. Nath, A.K. Das, I. Dasgupta, G.P. Das, Phys. Rev. B 75, 144404 (2007)
[6]	A. Singhal, S.N. Acharya, A.K. Tyagi, P.K. Manna, S.M. Yusuf, Mater. Sci. Eng. B 153, 47 (2008)
[7]	S. Kumar, S. Mukherjee, R. Kr, S. Singh, A.K. J. Appl. Phys. 110, 103508(2011)
[8]	R. Janisch, P. Gopaland, N.A. Spaldin, J. Phys.: Condens. Matter 17, R657 (2005)
[9]	J.M.D. Appl. Phys. Lett. 84, 1332(2004)
[10]	M.V. Limaye, S.B. Singh, R. Das, P. Poddar, S.K. Kulkarni, J. Solid State Chem. 184, 391(2011)
[11]	G.J. Huang, J.B. Wang, X.L. Zhong, G.C. Zhou, H.L. Yan, J. Mater. Sci. 42, 6464(2007)
[12]	W.H. Meiklejohn, C.P. Bean, Phys. Rev. 102, 1413(1956)
[13]	J. Nogués, I.K. Schuller, J. Magn. Magn. Mater. 192, 203(1999)
[14]	J. Noguesa, J. Sorta, V. Langlaisb, V. Skumryeva, S. Surinachb, J.S. Munozb, M.D. Baro, Phys. Rep. 422, 65(2005)
[15]	S. Giri, M. Patra, S. Majumdar, J. Phys.: Condens. Matter 23, 073201 (2011)
[16]	Z.C. Chen, L.J. Zhuge, X.M. Wu, Y.D. Meng, Thin Solid Films 515, 5462 (2007)
[17]	C. Wang, Z. Chen, Y. He, L. Li, D. Zhang, Appl. Surf. Sci. 255, 6881(2009)
[18]	K.J. Kim, Y.R. Park, J. Appl. Phys. 96, 4150(2004)
[19]	L. Xu, X. Li, J. Cryst. Growth 312, 851 (2010)
[20]	G.K. Williamson, W.H. Hall, Acta Metall. 1, 22(1953)
[21]	S. Biswas, S. Sarkar, D. De, D. De, S. Sabyasachi, R. Ray, Indian J. Phys. 89, 703(2015)
[22]	G. Murugadoss, J. Mater. Sci. Technol. 28, 587(2012)
[23]	A. Parra-Palomino, O. Perales-Perez, R. Singhal, M. Tomar, J. Hwang, P.M. Voyles, J. Appl. Phys. 103, 07D121 (2008)
[24]	S. Selmani, H. Abdullah, Funct. Mater. Lett. 4, 101(2011)
[25]	A. Srivastava, N. Kumar, S. Khare, Opto-Electron. Rev. 22, 68(2014)
[26]	S. Kumar, K. Asokan, R.K. Singh, S. Chatterjee, D. Kanjilalb, A.K. Ghosh, RSC Adv. 4, 62123(2014)
[27]	A. Singhal, S.N. Achary, J. Manjanna, O.D. Jayakumar, R.M. Kadam, A.K. Tyagi, J. Phys. Chem. C 113, 3600 (2009)
[28]	R. Elilarassi, G. Chandrasekaran, Front. Mater. Sci. 7, 196(2013)
[29]	S. Kumar, N. Tiwari, S.N. Jha, S. Chatterjee, D. Bhattacharyya, N.K. Sahoo, A.K. Ghosh, RSC Adv. 5, 94658(2015)
[30]	Z. Ren, G. Xu, X. Wei, Y. Liu, X. Hou, P. Du, W. Weng, G. Shen, G. Han, Appl. Phys. Lett.