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FIZIKA A 18 (2009) 4 , 173-184
 
SOME CHARACTERISTIC PHYSICAL PROPERTIES OF NICKEL OXIDE POWDER
S. A. GADa, M. BOSHTAa, A. M. ABO EL-SOUDa
and M. Z. MOSTAFAb
aSolid State Physics Department, National Research Center, El-Boohoos
str., 12311 Dokki, Giza, Egypt
bCeramic, Refractories and Building Materials Department, National
Research Center, El-Bohoos st., 11312 Dokki, Giza, Egypt
Received 27 October 2008; Revised manuscript received 15
April 2009
Accepted 18 November 2009 Online 31 December 2009
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
sm 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.
PACS numbers: 77.84.Bw, 81.05.Je, 72.80.Jc
UDC 538.911, 538.93, 537.312
Keywords: nickel oxide powder, crystal structure, energy gap, electrical
conductivity, electron spin resonance spectra
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