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Sains Malaysiana 39(6)(2010):
1007–1013
Dependence of Pyroelectric Properties of La0.03Sr0.255Ba0.7Nb2-yTiyO(6-y/2) Ceramic
on Electric Field, Grain Refinement and Ti/Nb Crystallite Sizes
(Kebergantungan
Sifat Piroelektrik Seramik La0.03Sr0.255Ba0.7Nb2-yTiyO(6-y/2) Terhadap Medan Elektrik dan Saiz
Hablur Ti/Nb)
Wee Chen Gan* & WanHaliza Abd. Majid
Solid State Research
Laboratory, Physics Department, University of Malaya
50603 Kuala Lumpur, Malaysia
Received: 14 August 2009 / Accepted:
1 April 2010
ABSTRACT
The
pyroelectric properties of La0.03Sr0.255Ba0.7Nb2-yTiyO(6-y/2) (LSBNT) ceramic pellets using several Ti/Nb ratios sintered at 1250¡C
for 5 h were investigated. The samples were subjected to several values of
electric fields in order to obtain the optimum electric field strength. The
pyroelectric coefficients, (p) were measured using the quasi-static method by applying
several heating rates. The results show that the Ti/Nb ratios and the dc poling
field, (Edc) influenced the measured
pyroelectric coefficient of the LSBNT ceramic pellets. The mean grain size of the particles as
obtained from scanning electron microscope (SEM) does not seem to give significant impact on the pyroelectric
coefficient of the ceramic pellets. However, the X-Ray diffraction (XRD) results indicate that the crystallite sizes of Ti and Nb of
these ceramic pellets after being treated with sintering process also influence
the measured pyroelectric coefficients of the ceramic pellets.
Keywords:
Ferroelectric ceramic; pyroelectric; spontaneous polarization
ABSTRAK
Sifat
piroelektrik La0.03Sr0.255Ba0.7Nb2-yTiyO(6-y/2) (LSBNT) pelet
seramik dengan nisbah Ti/Nb yang berlainan selepas dipanaskan pada suhu 1250¡C
selama 5 jam telah dikaji. Sampel dikenakan medan elektrik yang berlainan
supaya ia mencapai keadaan medan elektrik yang optimum. Pekali piroelektrik,
(p) ditentukan dengan menggunakan kaedah kuasi-statik. Keputusan yang didapati
menunjukkan nisbah Ti/Nb dan medan kutub arus terus, (Edc) mempengaruhi pekali piroelektrik seramik LSBNT yang dikaji. Saiz butiran seperti yang didapati daripada
mikroskop imbiasan elektron (SEM)
tidak menunjukkan sebarang pengaruh yang ketara terhadap pekalian piroelektrik
seramik. Bagaimanapun, keputusan pembiasan sinar-X (XRD) yang diperolehi menunjukkan saiz hablur Ti dan Nb seramik yang
telah dirawat dengan proses pemanasan menpengaruhi pekali piroelektrik seramik.
Kata kunci:
Pengutuban spontan; piroelektrik; seramik feroelektrik
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*Corresponding author; email: wcgan1981@yahoo.com.sg
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