Evolution of dielectric and ferroelectric relaxor states in Al3+-doped BaTiO3

Abstract

In ferroelectric BaTiO3, we report the evolution of the Dielectric Relaxor and Ferroelectric Relaxor states as a function of B-site doped Al3+ concentration. The relaxor states occur after the paraelectric-ferroelectric phase transition upon cooling. Two different mechanisms are proposed; one based on migration of oxygen vacancies for symmetry-confirmation and the other based on disruption of long-range ferroelectric order by high concentrations of Al3+ ions at the B-site.

Enhancing properties of lead-free ferroelectric BaTiO3 through doping

“…For example, BaTi 0.9992 Al 0.0008 O 3 has a slightly lower T C of 390 K and an increased T O−T of 324 K compared to pure BaTiO 3 . [64] In summary, the domain walls movement significantly affect the dielectric properties of BaTiO 3 ceramics. Donor doping increases the domain walls mobility and permittivity increases as a consequence.…”

Defects and Aliovalent Doping Engineering in Electroceramics

“…For the (Bi 1/2 Na 1/2 )­TiO 3 system, the typical examples involve Mn 2+/3+ :(Bi 1/2 Na 1/2 )­TiO 3 , Fe 3+ :(Bi 1/2 Na 1/2 )­TiO 3 , Fe 3+ :(Bi 1/2 Na 1/2 )­TiO 3 –BaTiO 3 , Cu 2+ :(Bi 1/2 Na 1/2 )­TiO 3 –BaTiO 3 , Mn 2+/3+ :(Bi 1/2 Na 1/2 )­TiO 3 –SrTiO 3 , Cu 2+ :(Bi 1/2 Na 1/2 )­TiO 3 –SrTiO 3 –BiFeO 3 , (Nb 5+ , Fe 3+ ):(Bi 1/2 Na 1/2 )­TiO 3 –BaTiO 3 -(K 0.5 Na 0.5 )­NbO 3 , Ta 5+ :(Bi 1/2 Na 1/2 )­TiO 3 -(Bi 1/2 K 1/2 )­TiO 3 –LiSbO 3 , and so on. For the BaTiO 3 system, the typical examples are Fe 3+ :BaTiO 3 , − Mn 2+/3+ :BaTiO 3 , Bi 3+ :(BaCa)­TiO 3 , Al 3+ :BaTiO 3 , , Pr 3+/4+ :(BaCa)­TiO 3 , Y 3+ :BaTiO 3 –BaZrO 3 –CaTiO 3 , and so on. For the BiFeO 3 system, the typical instances involve Ca 2+ :BiFeO 3 , , Ni 2+ :BiFeO 3 , Mn 2+/3+ :BiFeO 3 , and so on.…”