Original scientific paper

Some characteristic physical properties of nickel oxide powder

S. A. Gad ; Solid State Physics Department, National Research Center, El-Boohoos str., 12311 Dokki, Giza, Egypt
M. Boshta ; Solid State Physics Department, National Research Center, El-Boohoos str., 12311 Dokki, Giza, Egypt
A. M. Abo El-Soud ; Solid State Physics Department, National Research Center, El-Boohoos str., 12311 Dokki, Giza, Egypt
M. Z. Mostafa ; Ceramic, Refractories and Building Materials Department, National Research Center, El-Bohoos st., 11312 Dokki, Giza, Egypt

Abstract

Nickel oxide powder was prepared by firing spec pure NiCO3 in air for 6 hours at different firing temperatures ranged from 800◦C to 1200◦C. The crystal structure of all samples is a cubic structural as obtained from XRD study. The diffuse reflectance of different samples of NiO was measured at room temperature in the wavelength range from 200 to 2000 nm. The energy gap of NiO samples was then deduced as well as the position and number of different transitions which were found to be dependent on the firing temperature. The electrical conductivity σm was measured over temperature range from 50◦C to 320◦C and frequency range from 42 Hz to 5 MHz. The conductivity decreases with increasing firing temperature and increases with frequency. The activation energy was calculated and was found to increase with increasing firing temperature. Electron spin resonance (ESR) spectra were recorded at room temperature as first derivatives using an X-band spectrometer with a magnetic field modulation of 100 kHz. The intensity of the ESR-spectra of NiO samples decreases with increasing firing temperature.

Keywords

Hrčak ID:

302729

URI

https://hrcak.srce.hr/302729

Publication date:

1.9.2009.

Article data in other languages: croatian

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