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Structure and Dielectric Properties of Pb(Sc 2/3 W 1/3 )O 3 –Pb(Zr/Ti)O 3 Relaxors
Author(s) -
Juhás Pavol,
Davies Peter K.,
Akbas Mehmet A.
Publication year - 2004
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2004.tb06364.x
Subject(s) - dielectric , materials science , perovskite (structure) , order (exchange) , ceramic , crystallography , crystal structure , solid solution , permittivity , analytical chemistry (journal) , mineralogy , chemistry , metallurgy , optoelectronics , chromatography , finance , economics
The structure and dielectric properties of (1− x )Pb(Sc 2/3 W 1/3 )O 3 –( x )Pb(Zr/Ti)O 3 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(Sc 2/3 W 1/3 )O 3 (PSW) can be described by a random‐site model with one cation site occupied by Sc 3+ and the other by a random distribution of (Sc 1/3 3+ W 2/3 6+ ). The ordering is destabilized in solid solutions of PSW with PbZrO 3 (PSW–PZ), but stabilized by PbTiO 3 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 ( T ɛ,max ) increases linearly with x ; however, for PSW–PT T ɛ,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, T ɛ,max increased by more than 60°C.