Effect of Cu 2 + Doping on Structural and Optical Properties of Synthetic Zn 0 . 5 CuxMg 0 . 5-xFe 2 O 4 ( x = 0 . 0 , 0 . 1 , 0 . 2 , 0 . 3 , 0 . 4 ) Nano-Ferrites

The samples of Zn0.5CuxMg0.5-xFe2O4 nanoparticle ferrites, with x= 0.0, 0.1, 0.2, 0.3, 0.4 were successfully synthesised. Structural and optical properties were investigated by X-ray Diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR) and UV-visible spectroscopy. The structural studies showed that all the samples prepared through the Co-precipitation method was a single phase of a face-cantered-Cubic (FCC) spinel symmetry structures with space group (SG): Fd-3m. In the series Zn0.5CuxMg0.5-xFe2O4, the lattice parameter was found to be 8.382 Å for x = 0 and was found to increase with copper concentration. The grain size obtained from the XRD data analyses was found to be in the range of 15.97 to 28.33 nm. The increased in the grain size may be due to the large ionic radius of Mg (0.86 Å) compared with Cu (0.73 Å). The FTIR spectroscopy confirmed the formation of spinel ferrite and showed the characteristics absorption bands around 580, 1112, 1382, 1682, 1632 and 2920 cm. The energy band gap was calculated for samples were found to be in the range 4.04 to 4.67 eV.


Introduction
Nanotechnology is considered one of the modern sciences that look for design- ing the smallest apparatus and it concentrates basically on substituting the particle structures or the atomic parts of the material towards realizing new structures and with the economic cost which should not exceed the raw material [1] [2].The Nanotechnology is also regarded as the basic future sciences that will gain an increasing demand in the field of industry, medicine and transferring and transport sector and also in the field of aviation, space and telecommunication [3] [4].The biological, chemical and material properties in the Nano-size, differ from the basic shapes and properties of an atom or material itself [5]  is the incorporation of same suitable nonmagnetic/diamagnetic impurities at the A or B sites [12] [13] [14].Many of synthesis methods were considered in previous studies for produce the Nano-particles with size in the range of 2 -100 nm.
In this work, Nano-ferrite samples of Zn 0.5 Cu x Mg 0.5-x Fe 2 O 4 were synthesised using co-precipitation method.The structural and optical properties were studied using X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR) and UV-Visible spectroscopy.The main purpose is to study the effect of copper substituted magnesium in the Zn 0.5 Cu x Mg 0.5-x Fe 2 O 4 Nano-ferrites.

Material and Method
The samples Zn 0.5 Cu x Mg 0.5-x Fe 2 O 4 ferrites nano-crystalline powder with compositions (x = 0.0,0.1,0.2,0.3,0.4) were prepared using high purity (Sigma,98%) of Sodium hydroxide 96% were used as primary components.A Specified amount of Oleic acid was added to the solution as surfactant and coating material.The Scherer equation [17].
At room temperature, the transmittance mode investigated for the sample by a (Satellite FTIR 5000 of the wavelength range of 400 to 4000 cm −1 ) where the important bands and peaks of spinel structure can be assigned.A Fourier transform infrared spectroscopy collected by KBr pellet method, the material mixed with KBr of ratio 1:100 for FTIR measurement between 400 and 2000 cm −1 [17] [18].
The UV-Visible absorption was investigated by UV Mini 1240 manufactured by Shimadzu company-Japan.Hydrochloric acid HCl was used as a reference for 100% absorbance [19].

X-Ray Result
Symmetry is important in the study of structural and optical properties of the nanoparticle ferrites.Figure 1 shows crystalline phases determination of the crystal structure, the lattice parameters and the space group.The spinal of single phase Zn 0.5 Cu 0.4 Mg 0.1 Fe 2 O 4 nano-ferrite, with composition (x = 0.4) after analysing the XRD patterns are well indexed using MDI jade 5 and full proof.The crystal structure is found to be cubic with space group Fd3m.The fined peaks are indexed as the following (220), (311), (400), and (511).The crystallite size, the lattice constant, volume, space group and density are listed in Table 1, and the crystal size is calculated using Scherer's equation [17] [18].0.94 cos where D is the average crystallite size, θ is the angle, λ is the incident of X-ray wavelength, while β is the (FWHM) of the highest intensity peak (311).The results of X-ray diffraction are listed in Table 1.
Figure 2 shows the intensity and 2θ for samples with a different concentration of copper crystalline size are found to the scattered in the range 20.94 nm up to 28.33 nm for different compositions.As the concentration of copper increases from x = 0.1 to 0.4, the lattice constant, a, increased from 8.375 Å to 8.397 Å.
The increasing in lattice constant is attributed due to the larger ionic radius of Advances in Nanoparticles   Mg 2+ (0.86 Å) compared with Cu 2+ (0.73 Å) [4].The results showed that the lattice parameter, a, was increased with copper concentration and attributed to the smaller ionic radius of magnesium nanoferrite by co-precipitation.Yue et al. [20], worked on the effect of copper on electromagnetic properties of (Mg 0.5-x Cu x Zn 0.5 )O(Fe 2 O 3 ) 0.98 ferrite and found that the density, grain size, permeability, curie temperature increased.Rezlescu et al. [21] also reported that the sintered density and resistivity of Mg 0.5-x Cu x Zn 0.5 + 0.5MgOFe 2 O 4 ferrite increased up to X = 0.3 whereas, permeability increased up to X = 0.4 [14].However, in this study; the effect of copper substituted magnesium Nano-ferrites by co-precipitation technique showed the lattice parameter increases from x = 0.1 to 0.4 when the Cu 2+ concentration was increased.
From Table 1 we can observe that the density and volume increase with increasing Cu content.The increase in density and volume may be due to the ionic of constituent ions.After analysing the XRD data, the structural studies showed that all the samples prepared through the co-precipitation method are single phase of a face-centred Cubic (FCC) spinel and the symmetry structures with space group SG: Fd-3m.
Figure 3 shows the relation between lattice parameters and concentration of copper.It can be observed that the lattice constants are increased as the concentration of copper further increase.

FTIR Analysis
Functional groups of the synthesize Zn 0.5 Cu x Mg 0.5-x Fe 2 O 4 are investigated by FTIR spectroscopy in the range of 400 to 4000 cm −1 .Figure 4 shows the spectra of all the ferrites has been used to locate the band positions which is listed in Table 2.
In the present study the absorption bands v 1 , v 2 , v 3 , v 4 and v 5 are found to be around 580, 1112, 1382, 1632 and 2920 cm −1 .
How to cite this paper: Ali, B.M., Siddig, M.A., Alsabah, Y.A., Elbadawi, A.A. and Ahmed, A.I. (2018) Effect of Cu 2+ Doping on Structural and Optical Properties of Synthetic Zn 0.5 CuxMg 0.5-x Fe 2 O 4 (x = 0.0, 0.1, B. M. Ali et al.DOI: 10.4236/anp.2018.71001 2 Advances in Nanoparticles solution of Fe(NO 3 ) 3 •9H 2 O, 0.4 M (25 ml), Mg(NO 3 ) 2 •6H 2 O, 0.2 M (25 ml), Cu(NO 3 ) 2 •3H 2 O, and Zn(NO 3 ) 2 •6H 2 O were first mixed and then slowly added 3 molarities of NaOH.The PH of the solution was constantly monitored as the NaOH solution was added.The reactant was constantly stirred using magnetic B. M. Ali et al.DOI: 10.4236/anp.2018.71001 3 Advances in Nanoparticles stirrer unit a pH level of (11-12) [7].The liquid precipitate was then brought to a reaction temperature of 80˚C and stirred for one hour.At this stage, the product contains some associated water which was removed by heating at 450˚C for 6 hours in temperature controlled muffle furnace Vulcan A-550 at a heating rate 10˚C/min.The final product obtained materials were ground into powder and then made ready for characterization using various techniques.X-ray diffraction (XRD) data collected by Shimadzu 6000 X-ray diffract meter with Cu-kα radiation of a wavelength of λ = 1.5406Å.At room temperature, with a nickel filter operating at 40 KV, 40 mA the data collected for the 2θ in 0.02-step size and five-second count time in 20˚ -80˚ range.The MDI jade 0.5 programs used for the XRD date analysis.The crystallite size (D) calculated by

Figure 3 .
Figure 3.The relation between lattice parameters and concentration.

Figure 4 .
Figure 4. FTIR spectra of Zn 0.5 Cu x Mg 0.5-x Fe 2 o 4 Nano ferrites of different concentration of Cu.

Table 2 .
Wave numbers and band gap energy of the Zn 0.5 Cu x Mg 0.5-x Fe 2 O 4 nano-ferrites samples.Cu 0.4 Fe 2 O 4 Advances in Nanoparticles