Ferroelectric Properties of Substituted Aurivillius Phases SrBi2Nb2-xMxO9 (M=Cr, Mo)

• DOI: 10.5012/bkcs.2002.23.10.1463
• Publication Date: 2010-07-08T02:44:48Z
• Authors: Kwang-Woo Jung; Kyungoh Choi; Hyeon-Yong Lee; S.-Y. Moon; Dongwoon Jung
• Keywords: 01 natural sciences; 0104 chemical sciences

Partially doped Aurivillius phases SrBi 2 Nb 2 - x M x O 9 (M=Cr and Mo) were successfully synthesized and characterized. The extent of the substitution was limited at ∼20 mole % because of the size differences between Nb 5 + and Cr 6 + , and between Nb 5 + and Mo 6 + . When the amount of substitution exceeded ∼20 mole%, the phases began to collapse and the second phases were made. The dielectric constants of substituted compounds were enlarged nevertheless Cr or Mo is substituted. The increment is bigger in the Mo substituted compound than in the Cr doped one although the Nb(Cr)O 6 octahedra could be more strongly distorted than the Nb(Mo)O 6 octahedra since the ionic size difference between Nb 5 + and of Cr 6 + is much bigger than that between Nb 5 + and Mo 6 + . Consequently, the dielectric constant of the substituted Aurivillius phase Bi 2 A n - 1 B n - x M x O 3 n + 1 depends on the extent of distortion of the BO 6 octahedra and more strongly on the polarizability of the metal.