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3.2. AFM
The surface morphological studies from AFM was carried out to confirm the actual size of the particles, their growth 
pattern and the distribution of the crystallites. Figure(4) provides a 3D profile of the surface on a nanoscaleof ZnO 
nanoparticles. 
 
Fig.4. AFM images of the prepared ZnO nanoparticle in 3D 

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Khalaf AL ABDULLAH et al. / Energy Procedia 119 (2017) 565–570 
567
2 
Khalaf AL ABDULLAH, Sahar AWDE/ Energy Procedia 00 (2017) 000–000 
important advantages of the sol–gel method are easiness of the synthesis, low temperature of The final 
decomposition and control on the chemical composition. These advantages make the sol-gel technique a very 
attractive preparation method. The aim of this study was to synthesize zinc oxide of low dimension and investigation 
of morphological and electrical properties. This method has novel features, which are of considerable interest due to 
its low cost, easy preparation and industrial viability. Synthesis of ZnO nanoparticles by a modified sol gel technique 
is reported by Zinc acetate dehydrate Zn (CH
3
COO)
2
. 2H
2
O precursor and calcined at 500 Co. The structural and 
electrical properties of ZnO have been studied by XRD, AFM, and MEGOHMMETER-M1500P. 
2. EXPERIMENTAL DETAILS 
For the synthesis of ZnO Nanopowder by a sol-gel method, (13g) of Zinc acetate dehydrate Zn (CH3COO) 
2
.2H
2
O 
was dissolved in methanol solution (0.6M) under continuous stirring. The mixed solution was stirred with a 
magnetic stirrer at 80
o
C for 2 hours to form a transparent sol; its pH was adjusted with ammonia between 9 and 11. 
After adjusting the pH by using pH Meter, the sol was dried at 100 
o
C for 1 hour, and then the temperature was 
increased up to 150 
o 
C until gelation occurred. The white precipitate formed after the evaporation was filtered, 
washed with methanol several times, dried at 200 
o 
C and then calcined in an oven at 500 
o 
C for 3 hours. The 
temperature of the dried powder was increased at the rate of 3
o
C/min to attain the required temperature (500
o
C). 
Finally, zinc oxide nanoparticle powders were weighed (4g) and pressed into 20 mm diameter and 2 mm height 
discs by 150 MPa pressure using a hydraulic press (Figure1). 
Fig.1 ZnO based varistor. 
The synthesized sample was characterized for their structure by X-ray diffraction (XRDLEYBOLD-TYPE1.03 
diffraction) with CuKα radiation (λ = 1.5148 Å) as incident radiation. The morphological surface of the ZnO 
nanoparticles was studied from AFM (easyScan2 FlexAFM- SAMPLE STAGE). The sintered sample at temperature 
1050 °C are covered by silver paste and heated at 600°C for 10 min for measuring the electrical characteristics (I-V) 
by using V-I source/measuring unit MEGOHMMETER-M1500P