Structure and Dielectric Properties of Pb(Sc2/3W1/3)O3-Pb(Zr/Ti)O3 Relaxors

• Published in: Journal of the American Ceramic Society 2004-11, Vol.87 (11), p.2086-2092
• Main Authors: Juhás, Pavol, Davies, Peter K., Akbas, Mehmet A.
• Format: Article
• Language: English
• Subjects: Applied sciences; Building materials. Ceramics. Glasses; Ceramic industries; Chemical industry and chemicals; Condensed matter: electronic structure, electrical, magnetic, and optical properties; dielectric materials/properties; Dielectric properties of solids and liquids; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Electrotechnical and electronic ceramics; Exact sciences and technology; Permittivity (dielectric function); Physics; relaxors; structure; Technical ceramics
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/j.1151-2916.2004.tb06364.x

The structure and dielectric properties of (1−x)Pb(Sc2/3W1/3)O3–(x)Pb(Zr/Ti)O3 ceramics have been investigated over a full substitution range. All compositions with x < 0.5 adopt a cubic perovskite structure; however, for x≤ 0.25 a doubled cell results from a 1:1 ordered distribution of the B‐site cations. The structural order in Pb(Sc2/3W1/3)O3 (PSW) can be described by a random‐site model with one cation site occupied by Sc3+ and the other by a random distribution of (Sc1/33+W2/36+). The ordering is destabilized in solid solutions of PSW with PbZrO3 (PSW–PZ), but stabilized by PbTiO3 in the (1−x)PSW–(x)PT system. The changes in order are accompanied by alterations in the dielectric response of the two systems. For PSW–PZ the temperature of the permittivity maximum (Tɛ,max) increases linearly with x; however, for PSW–PT Tɛ,max decreases in the ordered region (up to x= 0.25) and then increases rapidly as the order is lost. Similar effects were produced by modifying the degree of order of (0.75)PSW–(0.25)PT; when the order parameter was reduced from ∼1.0 to ∼0.65, Tɛ,max increased by more than 60°C.