Undoped zinc oxide (ZnO) has been prepared at various growth temperatures by conventional sintering process. The morphology and crystalline properties of ZnO pellets were examined by scanning electron microscopy, atomic force microscopy and X-ray diffraction. It has revealed that the grain size and surface roughness tends to increase by increasing the sintering temperature. XRD analysis showed that all samples are polycrystalline with a hexagonal wurtzite structure. The alignment of ZnO grains along the (10.0) plane was enhanced as the temperature increased. Interestingly, the compressive stress was found to decrease drastically from –0.62 GPa at 700°C to –0.2 MPa at 1000°C. This improvement in film structure seems to enhance considerably the dielectric properties for the samples sintering at high temperatures. Results show an increase of dielectric constant and a decrease of electrical resistivity when increasing the sintering temperature.
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