Synthesis of Fe Doped Zno Spintronic Nano Powders by Solution Combustion Method & There Characterization

Synthesis of Fe Doped Zno Spintronic Nano Powders by Solution Combustion Method & There Characterization

Hansaraj N.Sahu

Department of Ceramic and cement technology

P.D.A College of Engineering, Kalaburgi, India

Baburao N.Sherikar

Department of Ceramic and cement technology

1. College of Engineering, Kalaburgi, India

   Abstract In this work Fe doped ZnO powders were prepared by solution Combustion method using Zinc nitrate and ferric nitrate as oxidizer and urea as fuel at 500C. The synthesized powders were characterized by XRD for phase analysis, SEM for microstructure and EDS for elemental analysis. The obtained XRD patterns of synthesized powder were identical with the standard peaks of ZnO (JCPDS card number 36-1451). SEM images taken at 25kX, 50kX show that crystalline powder with the formation of agglomerates of size 300-400nm formed by nano powder of ZnO of 18-30mm..The crystallite size of the powder ranges between 18-27nm, when calculated using Scherer formula.

   Keywords Combustion, Zinc nitrate, Ferric nitrate, Urea.

   1. INTRODUCTION

      ZnO has a wide band gap of 3.37 eV and a large excitation binding energy of 60 meV, which can be obtained in a hexagonal wurtzite crystalline structure [1]. ZnO has various applications such as ultraviolet opto-electronic devices, transparent high power, high frequency electronic devices, piezo-electronic transducers and chemical gas sensors [2], conducting electrode in solar cells and thin-film transistor [3]. Doping with transitional metal elements leads to many interesting properties of ZnO. Currently, much experimental and theoretical research is based on dilute magnetic semiconductors (DMS) on ZnO doped with transition metal (TM) ions such as Mn, Fe and Co, since the predicted room temperature ferromagnetism in the DMS may be useful in spintronics[4].

      Spintronics which is also known as spin electronics or Flextronics, its the study of the intrinsic spin of the electron and its associated magnetic moment, in addition to its fundamental electronic charge, in solid-state devices.

      Up to now, various approaches have been applied to prepare TM doped ZnO, such as sol-gel [5-9], thermal decomposition solid-state route [10-11], co-precipitation [12-13], chemical vapour deposition [14], solution combustion synthesis [15], by using different chemical precursors, Till now no one reported synthesis of ZnO doped with Fe using urea as fuel by solution combustion synthesis. In the present investigation, we have used the solution

      combustion technique to prepare transition metal Fe doped ZnO (Zn1x FexO, where x = 0.01, 0.03, 0.05, 0.07, 0.1)

      powder using urea fuel because this technique is simple, fast,

      gives homogeneous product , involves low cost equipment and raw materials [16].

   2. EXPERIMENTAL DETAILS

      1. Raw materials used

         Zinc nitrate hexa-hydrate (Zn(NO3)2.6H2O) ferric nitrate nano-hydrate (Fe(NO3)3.9H2O), Urea (NH2CONH2).

      2. Solution Combustion Synthesis of ZnO

         . The Fe doped ZnO ( Zn1x FexO , where x = 0.01, 0.03, 0.05, 0.07, 0.1 or 1%, 3%, 5% 7% 10% of Fe in Zn)

         powders were prepared by solution combustion process by using ferric nitrate and zinc nitrate as oxidizer and urea as fuel. The sample coding was done as per Table 1. The amount of chemicals were weighed as from the Table 2 and mixed in beaker. With adding distilled water the beaker was shaked untill it becomes transparent solution.The solution was taken in to the muffle furnace maintained at 500. Initially the chemicals boil for certain minutes to vaporise the water present in it. Then temperature of the solution increase simultaneously forming of froth. Then suddenly flame forms ending with the ash of desire composition with brown color.

         The combustion reaction characteristics and the combustion details like expected product, yield obtained, and amount of chemicals taken and moles of chemical precursor and number of moles of fuel taken are shown in Table 2. The combustion details like nature of combustion combustion time, color of the flame, flame type, are shown in Table 1.

         All obtained powders were characterized by XRD, Under the equilibrium conditions the reaction equations in these fuels nitrate systems for preparation of ZnO by urea fuel can be represented as below.

         (1-x)Zn (NO3)2.6H2O+ xFe (NO3)39H20+1.66 NH2CONH2

         Zn(1-x) Fex O +1.66 CO2+(2.66+0.5x)N2+(9.32+3x)H2O

         . (1)

      3. Phase analysis by X-ray diffraction (XRD)

      X-ray diffraction studies were carried out for phase confirmation and calculating crystallite size of the milled samples, using D8-Advance-Bruker machine with Cu-K (wavelength of Cu-K () ~1.5406 Ã…) radiations for all the measurements. Ni filter was used to attenuate K lines. The crystallite size of powders was calculated using Scherrers formula.

      40000

      35000

      Intensity (cps)

      30000

      25000

      20000

      15000

      10000

      5000

      0

      Fe (0.01) doped ZnO

      (110)

      (002)

      (101)

      (102)

      (110)

      (103)

      (112)

      10 20 30 40 50 60 70 80

      2 in (degree)

      d =K/ cos……………..(2)

      Where, is the full width at half maximum (FWHM) of diffracted peaks in degrees, d stands for the liner dimension of particles in meters, refers to Braggs angle in degrees K is the shape factor, generally known as a numerical constant and evaluated as 0.93 and depends on shape of crystallites.

   3. RESULT AND DISCUSSION

      Intensity (cps)

      Figure.1-5 show the XRD patterns of the synthesized 1, 3, 5, 7, 10% Fe doped ZnO ( Zn(1-x) FexO where X=0.01, 0.03, 0.05, 0.07, 0.1) powders respectively prepared by solution combustion synthesis. The patterns are found to be in good agreement with the standard peak positions of ZnO (JCPDS Card No. 36-1451). These peaks reveal that all the investigated samples are nano crystalline powder of hexagonal wurtzite structure. The crystallite size of Fe-doped ZnO powder was 18-27nm when calculated using Scherrers formula and the data is given in Table 3.

      Figure 6 shows SEM images of 0.01(1%) Fe doped ZnO powders. The powders were agglomerates in the size ranging between 300-400nm. The agglomerates were formed by crystallites of the size ranging between 18-30nm, which was in relevance to the crystallite size obtained using Scherrers formula. Figure.7 shows the energy dispersive X- ray analysis (EDS) spectrum of ZnO confirming the presence of all elements of ZnO such as Zn, Fe, O.

      20000

      18000

      16000

      14000

      12000

      10000

      8000

      6000

      4000

      2000

      Fig. 1. XRD pattern of 1% Fe doped ZnO

      Fe (0.03) doped ZnO

      (110)

      (002)

      (101)

      (102)

      (110)

      (103)

      (112)

      20 40 60 80

      in (degree)

      Fig. 2. XRD pattern of 3% Fe doped ZnO

      (101)

      35000

      Fe (0.05) doped ZnO

      30000

      Intensity (cps)

      (110)

      (002)

      25000

      (110)

      (103)

      20000

      (102)

      (112)

      15000

      10000

      5000Figure 3.XRD pattern of Fe (0.05) doped ZnO

      0

      10 20 30 40 50 60 70 80

      2 in (degree)

      50000

      Intensity in cps

      40000

      30000

      20000

      10000

      0

      Fe (0.1) doped ZnO

      (110)

      (002)

      (101)

      (102)

      (110)

      (103)

      (112)

      20 40 60 80

      2 in (degree)

      Fig 3.XRD pattern of 5% Fe doped nO

      Fig 5. XRD pattern of 10% Fe doped ZnO

      12000

      10000

      Intensity (cps)

      8000

      6000

      4000

      2000

      0

      Fe (0.07) doped ZnO

      (110)

      (002)

      (101)

      (102)

      (110)

      (103)

      (112)

      20 40 60 80

      2 in (degree)

      Fig 4. XRD pattern of 7% Fe ) doped ZnO

      Table.1 Characteristics of the combustion reaction to produce ZnO
      Sl No	Sample code	Doping %	Samples	Color	Combusti on type	Combustion time
      1	ZNH01	1	(2.94) Zn(NO3)3.6H2O + (0.029) Fe(NO3)3.9H2O + NH2CONH2	Brown	flame	5.42min
      2	ZNH02	3	(2.88) Zn(NO3)3.6H2O + (0.08)Fe(NO3)3.9H2O+NH2CON H2	Brown	flame	4.48min
      3	ZNH03	5	(2.82) Zn(NO3)3.6H2O+ (0.145) Fe(NO3)3.9H2O+NH2CONH2	Brown	flame	5.23min
      4	ZNH04	7	(2.76) Zn(NO3)3.6H2O+ (0.20) Fe(NO3)3.9H2O+NH2CONH2	Brown	flame	4.41min
      5	ZNH05	10	(2.67) Zn(NO3)3.6H2O+ (0.29) Fe(NO3)3.9H2O+NH2CONH2	Brown	flame	5.09min

      Table.2 Amount of urea fuel and oxidizers, used for the combustion reaction to produce ZnO
      Sl No	Doping %	Zn(NO3)3.6H2O in (gm)	Fe(NO3)3.9H2O in (gm)	Fuel urea in (gm)	Expected powders in (gm)	Obtained powders in (gm)
      01	1	2.94	0.04	1.0	0.8	0.89
      02	3	2.88	0.12	1.0	0.8	0.78
      03	5	2.82	0.2	1.0	0.8	0.69
      04	7	2.76	0.28	1.0	0.8	0.63
      05	10	2.67	0.4	1.0	0.8	0.62

      Table 3.Effect of doping on Crystallite size
      Doping %	2			cos	d = K / cos in (nm)
      1	36.37	0.42	18.185	0.9500	20.80
      3	36.61	0.37	18.305	0.9494	23.63
      5	36.50	0.32	18.25	0.9496	27.31
      7	36.80	0.39	18.4	0.9488	22.43
      10	36.58	0.47	18.29	0.9494	18.6

      1. Magnification=25 k

      2. Magnification=50 k

Fig 6. SEM images of 1% Fe doped ZnO (a) at 25 k Magnification

(b) at 50k Magnification

Fig.7 The EDS spectrum of (1%) Fe doped ZnO

CONCLUSION

For the first time Fe doped ZnO ( Zn1x FexO , where x = 0.01, 0.03, 0.05, 0.07, 0.1 or 1%, 3%, 5% 7% 10% of Fe in

Zn) powders were synthesized by solution combustion method. The XRD patterns of all the samples show the formation of pure ZnO by comparing with standard JCPDS card no 36-1451. Up to 10% of Fe was soluble in ZnO. No impurity of iron oxide was present in XRD pattern. SEM images of the 1%Fe doped ZnO shows forrmation of aglomerate of ZnO of size 300 – 400 nm, formed by nano powder of size 18-30nm.

ACKNOWLEDGMENT

One of the author's of this paper Hansaraj Sahu expresses deep sense of gratitude to Prof. Balaram Sahoo (IISc), Dr. Shivanand Chanakotte (IISc), Pawan Rangdal (PDA College of Engineering, Kalaburgi) for thesis help & carrying out XRD characterization of the work.

REFERENCES

1. H.Ohno. Making nonmagnetic semiconductors ferromagneticAmerican Association for the advancement of Science (AAAS) Vol.281 Issue 5379, 951-956 August (1998) DOI: 10.1126/science.281.5379.951, 951, ;281 (1998).

2. Tomasz Dietl. " Dilute magnetic Semiconductors; Functional ferromagnet Nature Materials 2, 646-648, (2003).

   DOI:10.1038/nmat989

3. S. A. Wolf, D. D. Awschalom, R. A. Buhrman, J. M."Daughton, S. von Molnár, M. L. Roukes, A. Y. Chtchelkanova, D. M. Treger. Spintronics: A Spin-Based Electronics Vision for the Future" Science 294, 1488(2001)

4. Bappaditya Pal and P K.Giri, "High temperature ferromagnetism and optical properties of Co doped ZnO nanoparticles", Journal of Applied Physics 108, 084322 (2010).

5. C. Aydn , M.S. Abd El-sadek , KaiboZheng , I.S. Yahia, F. Yakuphanoglu, "Synthesis, diffused reflectance and electrical properties of nanocrystalline Fe-doped ZnO via solgel calcination technique", Optics & Laser Technology 48 44745,2 (2013)

6. A. Goktas , I.H. Mutlu, Y. Yamada, "Influence of Fe-doping on the structural, optical, and magnetic properties of ZnO thin films prepared by solgel method", Superlattices and Microstructures 57 (2013) 139149,(2013).

7. J.N. Hasnidawani, H.N. Azlina , H. Norita, N.N. Bonnia, S. Ratim2,E And E.S. Ali. "Synthesis of ZnO Nanostructures Using Sol-Gel Method". Procedia Chemistry 19, 211 216 ( 2016 )

8. Muneer M. Ba-Abbad, Abdul Amir H.Kadhum , Abu BakarMohamad, MohdS.Takriff , Kamaruzzaman Sopian, "Visible light photocatalytic activity of Fe3+-doped ZnO nanoparticle prepared via solgel technique", Chemosphere 91 16041611 (2013).

9. Rezq Naji Aljawfi, S. Mollah, Rezq Naji Aljawfi, S. Mollah, Journal of Magnetism and Magnetic Materials 323, 3126 3132 (2011).

10. S. Venkata prasad Bhat, F.L. Deepak, "Tuning the band gap of ZnO by substitution with Mn2+, Co2+ and Ni2+", Solid State Communications 13,5 345347, (2005).

11. Shuxia Guoa,b ,n, Zuliang Du," Influence of defects on magnetism of Co-doped ZnO", Journal of Magnetism and Magnetic Materials 324 782785 (2012)

12. Vijaya prasath Gandhi,Ravi Ganesan, Haja Hameed Abdu lrahman Syed ahamed,and Mahalingam Thaiyan, "Effect of Cobalt Doping on Structural, Optical, and Magneti cProperties of ZnO Nanoparticles Synthesized by Coprecipitation Method", Phys. Chem. C 2014, 118, 97159725, ( 2014).

13. Rosari Saleh , SuhendroPurboPrakoso , Adel Fishli, "The influence of Fe doping on the structural, magnetic and optical properties of nanocrystalline ZnO particles", Journal of Magnetism and Magnetic Materials 324 (2012) 665 670,(2011).

14. V.K. Sharma, M.Najim , A.K.Srivastava , G.D.Varma, "Structural and magnetic studies on transition metal (Mn, Co) doped ZnO nanoparticle"s, Journal of Magnetism and Magnetic Materials 324, 683689 (2012).

15. M.L. Dineshaa, H.S. Jayannaa, S. Ashokab, G.T. Chandrappa, "Temperature dependent electrical conductivity of Fe doped ZnO nanoparticles prepared by solution combustion method", Journal of Alloys and Compunds 485 (2009) 538541,(2009).

16. K.C.Patil, Mimani, T. Mater, "Solution combustion synthesis of nanoscale oxides and their composites" S. Phys. Mech. 4, 134137,( 2001).