Synthesis and Characterization of Nickel-zinc Spinel Ferrite by Sol-gel Autocombustion Technique

Content Provider	Semantic Scholar
Author	Kakade, G. N. Shengule, D. R.
Copyright Year	2017
Abstract	The spinel ferrite can be synthesized in nano crystalline form using various methods-such as chemical co-precipitation,hydrothermal sol-gel etc. we have synthesized nanocrystalline Nickel-Zinc ferrite by sol-gel auto combustion method. The prepared sample was sintered at 700c for 6 hr. Structural analysis of prepared sample was examined by using x-ray diffraction. The surface morphology was investigated by SEM. KEYWORDNi-Zn spinel ferrite, sol-gel autocombustion technique,XRD, SEM. 1.INTRODUCTIONFerrites are ferrimagnetic materials with good magnetic,dielectric properties and large number of technological applications in satellite, communication, memory devices, computers, components,filter components,antenna rods, transformer cores etc. because of their good electronic and magnetic properties[1].The high electrical resistivity, low eddy current and dielectric losses, SYNTHESIS AND CHARACTERIZATION OF NICKEL-ZINC SPINEL FERRITE BY SOL-GEL AUTOCOMBUSTION TECHNIQUE ________________________________________________________________________________________ ___________________________________________________________________________________________ Available online at www.lbp.world 2 moderate saturation magnetization, easy and low cost of preparation, high curie temperature and high permeability are the remarkable characterization of ferrite material which makes them useful in variety of applications. The properties of ferrites depends upon magnetic interaction, cation distribution in the two sub lattice, method of preparation, preparative parameters, type and amount of dopant etc.[2-4].The dielectric properties of ferrites are depends upon different factors including the method of preparation ,chemical composition and grain structure. Ni-Zn ferrite possess mixed spinel has high electric resistivity, low eddy current and dielectric loss, moderate saturation magnetization, high curie temperature and wide applications in many fields[5-6]. Taking into consideration the importance of Ni-Zn ferrite the aim of present work was to synthesize metal ferric nanoparticle of mixed nickel-zinc spinel(Ni0.65Zn0.35Fe2O4) ferrite using wet chemical sol-gel auto combustion method and find out various structural, morphological and dielectric properties. 2. EXPERIMENTAL In the synthesis of Nickel -Zinc spinel ferrite AR grade with high purity (99.99 %) nitrates of metal ions(Nickel, Zinc and ferric ) were used and L-Ascorbic acid was used as fuel.All as nitrates and LAscorbic acid as per calculation was taken and dissolved in minimum amount of double distilled water in separate beaker. The metal nitrate to fuel ratio was taken 1:3. All thesesolution are mixed homogenously in single beaker by continues stirring. Ammonia was added to adjust thep H ofvalue 8 of initial solution. This solution was evaporated at 75 0 c to get a dense sticky gel, then temperature was increased to 110 0 c for the dehydration process. The temperature was then increased rapidly and when it reached approximately 120 0 c large of gases((CO2, H2O, N2) were liberated and dark brown power was produced through combustion process. The prepared power of Ni-Zn spinel ferrite is sintered at 700 0 c for 6 h and various properties of Ni-Zn ferrite were studied. 3. RESULTS AND DISCUSSIONS A) Structuralproperties:X-ray diffraction(XRD) is an important tool to check the phase purity and crystal structure of prepared sample.In present study x-ray diffraction technique was used to characterize Ni0.65Zn0.35Fe2O4 spinel ferrite sintered at 700 0 c for its phase purity. X-ray diffraction pattern recoded at room temperature for sample is shown in fig1 Fig 1 XRD pattern of Ni0.65Zn0.35Fe2O4 nanoparticle at temperature 700 c. SYNTHESIS AND CHARACTERIZATION OF NICKEL-ZINC SPINEL FERRITE BY SOL-GEL AUTOCOMBUSTION TECHNIQUE ________________________________________________________________________________________ ___________________________________________________________________________________________ Available online at www.lbp.world 3 A close observation of XRD pattern suggest that planes with miller indices (220),(311),(222), (400),(422),(511), and (440) belongs to cubic spinel structure. These planes have sufficient intensity and are broader. The values of Bragg’s angle 2Θ,inter planer spacing d and intensity of various planes for sample are given in Table 1 Table 1: Miller indices (h k l), Bragg’s angle (θ) inter planar spacing (d), intensity (I) and relative intensityratio(I/I0) of Ni0.65Zn0.35Fe2O4 nanoparticle for 700 0 c (h k l) 2θ (degree) θ (degree) sin(θ) sin(θ)/ d (Å) I (a.u) I/IO (220) 30.422 15.211 0.262 0.17017 2.935 1901.3 54 (311) 35.789 17.895 0.307 0.19929 2.506 3508.0 100 (222) 37.423 18.712 0.321 0.20807 2.401 1404.9 40 (400) 43.437 21.719 0.370 0.24001 2.081 1686.0 48 (422) 53.834 26.917 0.453 0.29361 1.701 1469.1 42 (511) 57.354 28.677 0.480 0.31124 1.605 1814.0 52 (440) 62.962 31.481 0.522 0.33870 1.475 1965.5 56 The most intense peak (311) observed in XRD pattern of sample is considered for determining the crystallite size. The crystallite size is obtained by using relation [7] The obtained values of crystallite size are given in table 2..From table 2 it is clear that crystallite size was 18 nm indicating nan crystalline nature of sample Table 2: Lattice parameter(a),X-ray density(dx),bulk density(dB),Porosity(P%),unit volume(v) and crystallite size(t) of Ni0.65Zn0.35Fe2o4 nanoparticle for 700 0 c Sintering temp. a dx dB P V t maintain at (Å) (gm/cm 3 ) (gm/cm 3 ) % (Å 3 ) (nm) 700 o C 8.324 5.4527 2.6317 51.73 576.76 18 Latticeconstant(a)of sample was calculated using standard relation for cubic spinel structure. From table 2 it is observed that lattice constant of Ni-Zn sample is in between lattice constant of pure Nickel ferrite and Zinc ferrite. X-raydensity (dx) of sample was calculated using following relation [8] and obtained value is presented in table 2. dx = 8M/NV gm/cm 3 M-molecular weight, N-Avogadro’s number and V=a unit cell volume. Bulkdensity (dB) of present sample was measured by using Archimedes principle. The value of bulk density is given in table 2,which is less as compared to x-ray density. SYNTHESIS AND CHARACTERIZATION OF NICKEL-ZINC SPINEL FERRITE BY SOL-GEL AUTOCOMBUSTION TECHNIQUE ________________________________________________________________________________________ ___________________________________________________________________________________________ Available online at www.lbp.world 4 Percentageporosity (P%) is calculated by taking known values of bulk density and x-ray density. The percentageporosity was calculated [9] and its value is given in table 2. Hopping length of tetrahedral and octahedral site (LA) and(LB) for the present sample was calculated using following relation[10]. LA = a√ (3)/4 Ǻ LB = a√(2)/4 Ǻ The value of hopping length LA and LB are given in table 3. Table 3: Hopping length (LA, LB), Tetrahedral bond (dAX),Octahedral bond (dBX),Tetra edge (dAXE) and Octa edge (dBXE) of Ni0.65Zn0.35Fe2O4 nanoparticles for (700 o C). Sintering dBXE temp. LA LB dAX dBX dAXE (Å) maintain at (Å) (Å) (Å) (Å) (Å) Shared Unshared 700 o C 3.6044 2.9430 1.8887 2.0323 3.0842 2.8017 2.9446 From table it is seen that hopping length LA is less than LB. The tetrahedral radius(rA) and octahedral radius(rB) for present sample were calculated using the following relations[11].and their values are given in table 4 rA = u − 1 4 a 3 − r O Ǻ rB = 5 8 − u a − r O Ǻ Where u is oxygen positional parameter(u =0.381) r(O) is radius of oxygen ion(1.32 A ) Tetrahedral and Octahedral edge:The structural parameters like tetrahedral edge and octahedral edge, shared and unshared were calculated using following relations[12]. dAX = a(3(u-1/4)) 1/2 Ǻ dBX = a[3u 2 -(11/4) u+(43/64)] 1/2 Ǻ Table 4: Ionic radii (rA, rB) Ni0.65Zn0.35Fe2O4 nanoparticles for (700 o C) Sintering temp. rA rB maintain at (Å) (Å) 700 o C 0.5687 0.7111 SYNTHESIS AND CHARACTERIZATION OF NICKEL-ZINC SPINEL FERRITE BY SOL-GEL AUTOCOMBUSTION TECHNIQUE ________________________________________________________________________________________ ___________________________________________________________________________________________ Available online at www.lbp.world 5 dAXE = a[2(2u-1/2)] 1/2 Ǻ dBXE = a[2(1-2u)]1/2 Ǻ dBXEU= a√ (4u 2 -3u+11/16)Ǻ Using the values of the lattice constant (a),the various other structural parameters like tetrahedral bond length(dAX),octahedral bond length(dBX),tetra edge(dAXE) and octa edge(dBXE) B. Morphological Characterization:Figure 2 SEM image of Ni0.65Zn0.35Fe2O4 nanoparticle at temperature 700 0 c. Surface morphology and average grain size of sample were determined by using scanning electron microscopy technique. The average grain size and specific surface area was calculated by relation[13] and presented in table 5 Gavg = 1.5L MN L-total test line length M-magnification N-total number of interception. Table 5 Grain size(G) and specific surface area(S) from SEM image for Ni0.65Zn0.35Fe2O4 nanoparticle at 700 0 c Sintering temp. Grain Size Specific maintain at (nm) Surface Area SEM (m 2 /g)
File Format	PDF HTM / HTML
Alternate Webpage(s)	http://oldwsrj.lbp.world/UploadedArticle/259.pdf
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article