Effects Of Strontium And Samarium Dopants On The Dielectric Properties Of Nickel Oxide
Nickel oxide (NiO) has attracted many researchers to explore its uses in apllications such as electrochoramic films, catalyst, gas sensor, diode and others. This is due to its high properties in chemical, electrical and optical stabilities. In this research, the effect of strontium ions (Sr2+) an...
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Format: | Thesis |
Language: | English |
Published: |
2017
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Online Access: | http://eprints.usm.my/46420/1/Effects%20Of%20Strontium%20And%20Samarium%20Dopants%20On%20The%20Dielectric%20Properties%20Of%20Nickel%20Oxide.pdf |
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Summary: | Nickel oxide (NiO) has attracted many researchers to explore its uses in
apllications such as electrochoramic films, catalyst, gas sensor, diode and others.
This is due to its high properties in chemical, electrical and optical stabilities. In this
research, the effect of strontium ions (Sr2+) and samarium ions (Sm3+) dopants on
dielectric properties of NiO was investigated. The dielectric properties studied in this
research are dielectric constant, εr and dielectric loss, tan δ. The electroceramic
system of Ni(1-x)SrxO, Ni(1-x)SmxO where x = 0.01 to 0.10 mol.% and SrxSmyNi(1-x-y)O,
where x = 0.03, y = 0.01 to 0.10 mol.% were prepared through solid state reaction
method. The samples were sintered at 1200 °C (3 hours soaking time), respectively.
Ni(1-x)SrxO was sintered at 1100 to 1300 ºC (1, 3, 6 and 10 hours soaking time).
Sample that sintered at 1200 ºC for 3 hours soaking time was identified as optimum
sintering parameters. X-Ray diffraction (XRD) analysis on sintered sample showed
the phase formation of Ni(1-x)SrxO, Ni(1-x)SmxO and Ni(1-x-y)SrxSmyO. Field Emission
Scanning Electron Microscopy (FESEM) observation on the Ni(1-x)SrxO shows the
grain size becoming larger with the increasing sintering temperature. The FESEM
was repeated with Ni(1-x)SmxO and Ni(1-x-y)SrxSmyO. The three systems showed their
grain size was increasing with increasing amount of dopants. The densification of
Ni(1-x)SrxO, Ni(1-x)SmxO and Ni(1-x-y)SrxSmyO was improved using Sr2+ and Sm3+
doping and the porosity decrease at higher dopant concentration (x, y). The dielectric
behaviour is measured in a wide frequency range of 1 to 1000 MHz. The increase of
εr is associated with the decrease of tan δ. The optimum composition for Ni(1-x)SrxO
and Ni(1-x)SmxO was obtained for x equals to 0.03 and 0.05 mol.% sample with
highest εr (3.24 x 103 and 4.85 x 103) and lowest tan δ (1.42 and 0.19) at 1 MHz. The
optimum composition for Ni(1-x-y)SrxSmyO, was obtained at y = 0.03 mol.% sample
with highest εr (5.41 x 103) and lowest tan δ (0.13) at 1 MHz. |
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