Prasad, Syam N and Varma, KBR (2003) Structural and dielectric properties of ferroelectric $Sr_1_-_xBa_xBi_2(Nb_0_._5Ta_0_._5)_2O_9$ and $Sr_0_._5Ba_0_._5Bi_2(Nb_1_-_yTa_y)_2O_9$ ceramics. In: Materials Research Bulletin, 38 (2). pp. 195-206.
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Ferroelectric $Sr_1_-_xBa_xBi_2(Nb_0_._5Ta_0_._5)_2O_9$and $Sr_0_._5Ba_0_._5Bi_2(Nb_1_−_yTa_y)_2O_9$ were synthesized by solid state reaction route. X-ray diffraction studies confirm the formation of single phase layered perovskite solid solutions over a wide range of compositions (x=y=0.0, 0.25, 0.50, 0.75 and 1). The lattice parameters and the Curie temperature $(T_c)$ have been found to have linear dependence on x and y. Transmission electron microscopy (TEM) suggest the lowering of orthorhombic distortion with increasing $Ba^2^+$ substitution. Variations in microstructural features as a function of x and y were monitored by scanning electron microscopy (SEM). The dielectric constant at room temperature increases with increase in both x and y. Interestingly $Ba^2^+$ substitution on $Sr^2^+$ site induces diffused phase transition and diffuseness increases with increasing $Ba^2^+$ concentration.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to Elsevier.|
|Keywords:||Ceramics;Electron microscopy;X-ray diffraction;Dielectric properties;Ferroelectricity|
|Department/Centre:||Division of Chemical Sciences > Materials Research Centre|
|Date Deposited:||02 Jun 2006|
|Last Modified:||19 Sep 2010 04:28|
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