Synthesis,Magnetic and optical properties of Ni_0.5Co_0.5 Al Nanoferrite by autocombution Technique

Synthesis,Magnetic and optical properties of Ni_0.5Co_0.5 Al Nanoferrite by autocombution Technique

Sopan M. Rathod

Nano Materials & Lasers Research Laboratory, Dept.of Physics, Abasaheb Garware College, Karve Road, Pune -411004,Maharashtra, INDIA

Raj R. Shah

Nano Materials & Lasers Research Laboratory, Dept.of Physics, Abasaheb Garware College, Karve Road, Pune -411004,Maharashtra, INDIA

Virendrakumar G. Deonikar

Nano Materials & Lasers Research Laboratory, Dept.of Physics, Abasaheb Garware College, Karve Road, Pune -411004,Maharashtra, INDIA

Pooja P. Mirage

Nano Materials & Lasers Research Laboratory, Dept. of Physics, Abasaheb Garware College, Karve Road, Pune -411004,Maharashtra, INDIA

Abstract A simple and low cost effective method involving sol-gel auto combustion at low temperature is used to synthesize Ni 0.5Co0.5 Alx Fe2-x O4. nanoparticles. The magnetic and optical properties of the synthesized samples were studied. The role of Al3+ substituted shows the formation of crystal phase, which was identified by X-ray diffraction method. The lattice constants decrease with the increasing in Al3+ containt. We report the synthesis of nanoparticles with crystalline size is in the range of 50 – 18 nm. The FTIR characterization shows the bond formation and synthesized material is ferrite. The Vibrating Sample Magnetometer was used to obtain the Hysteresis parameters. The magnetic properties of the samples shows remarkable changes with change of Al3+ percentage. UV-spectroscopy, to calculate the band gap energy is in the semiconductor range so that prepared sample is in the nature of semiconductor.

Keywords; sol-gel, Ni-Co nanoferrite, FTIR, XRD, VSM and UV

I. INTRODUCTION:

Ferrite nanoparticles are of great interest because of their scientific aspect and applications in permanent magnets, targeted drug delivery and high density information storage devices. From crystal structure point of view, ferrites are generally divided into two groups: cubic or spinel ferrites and hexagonal or hexaferrites [1,2]

Cobalt ferrite is a well known hard magnetic material with a high coercivity and a moderate magnetization. These properties along with its great physical and chemical stabilities, make CoFe2O4 nanoparticles suitable for many practical applications such as audio/ video tapes, high density digital recording disks, etc.[3-4]. On other hand Nickel ferrite is a typical soft magnetic material [5], which has many applications in electronic devices, such as inductors and transformator cores[6]. Aluminum and Chromium substituted Co-Ni spinel nano ferrites were prepared by sol-gel auto combustion method were investigated crystallite size estimated from peak(311) was

lattice parameter studied in the range of 120-70nm and 8.350

8.300 respectively. [8]. Nickel substituted cobalt ferrites are highly resistive and magnetostrictive. Studies of Van Uitert and Jilg showed that a very large increase at room temperature respectively of nickel ferrite is achieved by substituting 1or 2 percent of cobalt ions.[9-10].

Particles with nanosize exhibit unique chemical and physical properties. In particular nano composite material composed of nanometric metal and metal oxide particles embedded in vitreous matrices reveal a variety of interesting magnetic, electric and catalytic properties. Ferrites are ferrimagnetic semiconductors that opened a new area in the physics of material science and the needful high resistivity ferrites led to synthesis of various ferrites. The electrical and magnetic properties of ferrites depend on the method of preparation [11], Site preference [9] and valance distribution [10]. Magnetic properties of magnetic nano materials particularly in ferrites materials also depend on their chemical composition and methods of synthesis [12]. The substitution effect and the change of the preparation condition are allowed to improve the properties of ferrites. Generally ferrites were commercially used in radio frequency circuits, transformer cores , antennas and for high speed digital tape.

In this investigation, the effect of Al3+ substitution in Ni 0.5Co0.5 fe2O4 are studied. The sol-gel method is used to synthesize the nanoparticles of Ni0.5Co0.5 Alx fe2-x O4. The structural, optical and magnetic properties of the synthesized samples have been discussed in the contents.

1. EXPERIMENTAL METHOD AND MATERIALS:

   Ni-Co-Al ferrite powders were synthesized by sol-gel auto combustion technique at low temperatures for different compositions Ni0.5 Co0.5 Alx Fe2-xO4 (where x=0.1, 0.2, 0.4, 0.8,). Raw materials are used in the experiments are AR grade nitrates i.e. Ni(NO3)2, Co(NO3)2, Al(NO3)2, Fe (NO ) and C H O is used as a fuel in the ratio 1:3. all

   in range 13-21nm[7]. Ni substituted cobalt ferrite nanoparticles

   2 3 2

   6 8 7

   were prepared by sol-gel method. The crystallite size and

   from Merck co. of purity of 99 % using stoichiometric

   Fig.1:FTIR of NiCoAl(x)Fe(2-x)O4; x=0.4

   ratio and dissolved in distilled water. The mixture of the raw material was stirrered at 80 0C on hot plate magneto- stirrer. Maintaining pH 7, it was continuously stirrered to obtain uniform gel. After 4-5 hours it converts from gel to ash form, which was sintered at 560 0C. The FTIR characterization shows the bond formation and synthesized material is ferrite. The structural and average grain size is studied by X-ray diffraction (XRD), it is in crystal nature and average particle size is 50 – 18 nm. Particle size decreases with increasing the percentage of Al3+. Also lattice constant, (hkl) planes and grain size was calculated by Braggs law and Scherers formulae. From VSM the magnetic properties of the samples show remarkable changes with change of Al3+ percentage. Optical properties studied from UV-spectroscopy to calculate the band gap energy increases with increasing Al3+ it is in the semiconductor range so that prepared sample confirms the nature of semiconductor material.

   The general chemical reaction of the synthesis sample is as follows

   6

   5

   4

   3

   2

   1 400 450 500 550 600 650 700 750 800 850 900 950 1000

   Wavelength nm

   Figure.3:UV spectra of NiCoAl(x)Fe(2-x)O4; x=0.4

   Ni(No3)6H2O+CO(NO3)2.6H2O+Al(NO3)2.9H2O+Fe(NO3)3. 9H2O + 3C6H8O7 NiCoAlFe2O4

   1000C For 5hrs

   NiCoAlFe2O4

2. RESULTS AND DISCUSION:

1. FTIR Spectroscopy:

   A%

   The FTIR ( Fourier Transform Infrared Spectrometer) characterization from figure 1shows the bond formation and two main metal oxygen bands at the range of 500- 600 cm-1 so that it is conform that the synthesized material is ferrite.

2. Optical (UV Spectroscopy)Properties:

   Optical properties were studied from UV- spectroscopy to calculate the band gap energy, it increases with increasing Al 3+ i.e. 2.13eV to 2.48eV. It is in the semiconductor range so that prepared sample is in the nature of semiconductor material.

3. XRD charecterization:

   Figure.2: UV spectra of NiCoAl(x)Fe(2-x)O4; x=0.2

   1 0 00

   80 0

   6 00

   W a v elen g th n m

   4 00

   2 0 0

   0

   1

   2

   3

   4

   5

   6

   N iC o A lF e2 O 4

   A%

   Figure 4 & 5 shows the X-ray diffraction (XRD) patterns of typical samples of Ni0.5 Co0.5 Alx Fe2-xO4 (where x= 0.1, 0.2, 0.4, 0.8,). The XRD patterns shows well developed diffraction line assigned to pure inverse spinel phase. The all measured RD peaks match well with the standard patterns of inverse spinel ferrite. Interplane distance and planes are calculated by Braggs diffraction law and index method using equation 1 and 2. The NiCoAlFe2O4 nanoparticles exhibit several diffraction peaks which can be indexed as cubic structure. The average crystalline size of the prepared NiCoAlFe2O4 nanoparticles was found 50nm & 18 nm for the composition of x= 0.1 & 0.8, by using Sherrers formula.The intensity & width of the Braggs peak Conforming good crystallinity & nano particle size it is also good agreement with research article [8].

   TABLE I. LATTICE PARAMETER AND PARTICLE SIZE OF

   511

   400

   2500

   400

   220

   3000

   x=0.2

   x=0.4

   3500

   311

   4000

   intensity a. u.

   NICOAL(X)FE(2-X)O4

   Composition x	Lattice constanta	t particle size nm	Inteplane distanced(311)
   0.1	8.273	50.22	0.2492
   0.2	8.290	37.114	0.2515
   0.4	8.293	34.34	0.2494
   0.8	8.306	18.35	0.2491

   220 400 511

   Figure4:XRD of NiCoAl(x)Fe(2-x)O4; x= 0.2 & 0.4

   70 80

   Figure: XRD of NiCoAl Fe2O4; x = 0.2 & 0.4

   60

   50

   2

   40

   30

   20

   500

   0

   440

   1500

   1000

   311

   2000

   TABLE II. VSM OF NICOAL(X)FE(2-X)O4

   Compo sition x	VSM of NiCoAl(x)Fe(2-x)O4
   	Hc (Oe)	Mr emu/gm	Ms emu/gm
   0.2	64013.8155	018.4945	033.9368
   0.4	59633.0797	016.7000	027.7333
   0.8	40251.5723	07.6070	017.1157

   x=0.1 x=0.8

   311

   1100

   1000

   The interplane distance were calculated by using braggs equation from the relation

   220

   900

   800

   n 2d sin

   [1]

   700

   400 511 440

   311

   600

   500

   400

   Intensity a. u.

   The lattice parameter a was calculated using following relation

   300

   220

   100

   0

   400 511 440

   200

   a d

   p k 2 l 2

   [2]

   2

   Figure 5: XRD of Ni Co Fe O , x= 0.1 & 0.8

   2 4

   Figure5:XRD of NiCoAl(x)Fe(2-x)O4; x= 0.1& 0.8

   80

   60

   40

   20

   Where ( hkl) is the miller indices, is the wavelength of X-ray radiation and is the Bragg angle. The results of interplane distance and lattice parameter are shown in table 1.

   The particle size were calculated using Scherrers formula

   0.9

   t cos

   [3]

   30

   20

   10

   0

   x=0.2 x=0.4 x=0.8

   40

   Where, t is the particle size, and is the FWHM ( full width half maxima) of the peak

   magnetic moment(emu/gm)

4. VSM charecterization (Hystreessis loop)

-20

-30

-40

Magnetic field strenth ( Oe X 1000)

200 400

0

-10 A

-400 -200

0.2

Figure 6 shows the magnetic properties of the synthesis samples, it shows that the compositions of Al3+ containt increase the Hc ( Coercievity) , Mr (Magnetic remenance) and Ms (Magnetic saturation) all are decreasing. The results are illustrated in table2.

3. Conclusion:

Figure6:VSM of NiCoAl(x)Fe(2-x)O4; x=0.2, 0.4 &0.8

The nanoferrites were synthesized using sol-gel technique. The increase in the Al3+ concentration gives the significant changes in the particle size and magnetic properties of the composition Ni0.5 Co0.5 Alx Fe2-xO4 (where x=0.1, 0.2, 0.4, 0.8,). The FT-IR spectroscopy study shows two main metal oxygen bands at in the range of 500-600 cm-1confirming the formation of single phase cubic inverse structure of Al3+ substitute in Ni-Co ferrite. The crystalline particle size were found that significantly decrease with increasing the Al3+

concentration it is in the range of 50- 18nm. The lattice parameter increases with increasing Al3+ in Ni-Co ferrite due to less ionic radii of Al 3+ . The UV study shows band gap energy increases with increase in Al 3+ concentration. It is in the range of semiconductor materials. So that synthesized samples is in the nature of semiconductor materials. From the hysteresis loop, it is clear that the synthesized sample converts from hard to soft ferrite with increasing Al 3+ containts.

ACKNOWLEDGMENT

I am thankful to the University Grants Commission of India, for their financial support during the research work as a UGC- minor research project. Also I thank to IISER (Indian Institute of Science Education and Research), Pune, TIFR (Tata Institute of Fundamental Research), Mumbai, for providing the characterizations facility. The Department of Physics University of Pune. I am thankful to the Department of Chemistry, Department of Physics, Abasaheb Garware college, for their kind cooperation and providing their infrastructure for the characterization purpose. I, also thank to all those giving all type of valuable help in doing the research work.

REFERENCES

1. H. Gul, F. Amin, A.Z. Abbasi, M. Anis-ur- Rehmanb, A. Maqsood,physical and magnetic charecterization of Co-precipited nanosize Co-Ni ferrite Scripta Materialia 56 (2007) 497.

2. K. Raj, R. Moskowitz, R. Casciari, Advances in ferrofluide technology Journal of Magnetism and Magnetic Materials 149 (1995) 174.

3. A. Meenakshisundaram, N. Gunasekaran, V. Srinivasan, Distribution of Metal ions in trnsition metals magnites AMn2O4, (A: Co,Ni,Cu or Zn) ; Physica Status Solidi A 69 (1982) K15.

4. V. Pallai, D.O. Shah, Synthesis of high coersivity Cobalt ferrite particles using water- in oil microemulsions Journal of Magnetism and Magnetic Materials 163 (1996) 243.

5. K. Maaz, W. Khalid, A. Mumtaz, S.K. Hasanain, Magnetic Characterization of Co 1-x Ni x Fe2 O4 nanoparticles prepared by co- preticipitation route J. Liu, J.L. Duan, Physica E 41 (2009) 593.

6. L.G. Van Uitert, High resistivity nickel ferrites the effect of minar additions of manganese or cobalt; Journal of Chemical Physics 24 (1956) 306.

7. Erum Pervaiz, I. H. Cul, Low temperature synthesis and enhanced electrical properties by substitution of Al 3+ and Cr 3+ in Co-Ni nanoferrites; Journal of Magnetism and Magnetic Materials, Vol 343 (2013), pp 194-202.

8. M. Mozaffari, J. Amighian, E. Darsheshdar, Magnetic and structural studies of Nickel substituted cobalt ferrite nanoparticles, synthesized by sol-gel method Journal of Magnetism and Magnetic materials vol. 350(2014),pp19-22.

9. J. Jiang, A facile method to Ni0.8 Co0.2 Fe2 O4 nanocrystalline via a refluxing route in ethylene glycol Materials Letters 61 (2007) 3239

10. S. Singhal, J. Singh, S.K Barthwal, Optical, Xray diffraction and magnetic properties of the cobalt substituted nickel crromium ferrite (fe2O4 synthesized using sol-gel auto combustion method , et al., Journal of Solid State Chemistry 178 (2005) 3183.

11. M.K. Shobana, S. Sankar, Synthesis and charecterization of Ni1-x Co x

    Fe2O4 nanoparticles Journal of Magnetism and Magnetic Materials 321

12. Souad Ammar,ArnaudHelfel, Magnetic properties of ultrafine cobalt ferriteparticles synthesized byhydrolysis in a polyol medium JournalofMaterialsChemistry1(2001)186.

13. SagarE.Shirsath,R.H.Kadam,AnilS.Gaikwad,AliGhasemi,AkimitsuMori sako, Effect of sintering temperature and the particle size on the structural and magnetic properties of nanocrystalline Li0.5Fe2.5O4 Journal ofMagnetismandMagneticMaterials323(2011)3104.