Effect of Pb substitution on the microstructure and ferroelectric properties of Ba0.7Sr0.3TiO3 ceramic

Abstract

Ferroelectric Ba 0.7 Sr 0.3 TiO 3 (BST) and partially Pb 2+ substituted for Ba 2+ ceramics (Ba 0.7 -x Pb x )Sr 0.3 TiO 3 (x=0.1-0.4, BPST) were prepared by using conventional solid-reaction method. XRD analysis shows that the samples microstructure changes from cubic phase to tetragonal one with the Pb 2+ content increasing. ESEM analysis shows that the Pb 2+ substituted samples have a denser and more uniform surface morphology than that of pure BST. Measured electrical properties suggest that the Pb 2+ substitution for Ba 2+ in the BST system enhances the ferroelectric performance obviously when x=0.2. In addition, the substitution increases the samples Curie temperature (T c ). (Ba 0.5 Pb 0.2 )Sr 0.3 TiO 3 ceramic has good ferroelectric properties measured at a maximal electric field of 30 kV/cm under the condition of room temperature. The corresponding saturated polarization (P s ), remnant polarization (P r ) and coercive field (E c ) is respectively 15.687 μC/cm 2 , 8.100 μC/cm 2 and 6.611 kV/cm. The measured T c of (Ba 0.5 Pb 0.2 )Sr 0.3 TiO 3 is 117 .℃

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