0000000000160634
AUTHOR
Nicolas Menguy
Influence of B-site chemical ordering on the dielectric response of the Pb(Sc1/2Nb1/2)O3relaxor
The influence of chemical B-site ordering between Sc3+ and Nb5+ cations on the properties of the Pb(Sc1/2Nb1/2)O3 (PSN) relaxor has been investigated. Depending of the degree of ordering, PSN exhibits different behaviours. For a completely disordered material, a relaxor–ferroelectric phase transition is observed at 379 K by DSC. Ordering between Sc3+ and Nb5+ cations on the B-site of the perovskite structure leads to a non-homogeneous material constituted of two phases: ordered and disordered phases. The phase transition temperature of the ordered phase is confirmed to be lower (346 K) than that of the disordered phase. It appears that the phase transition of the disordered phase is shifted…
Study of the spontaneous relaxor to normal ferroelectric phase transition in la-doped lead titanate
Abstract Highly lanthanum doped lead titanate ceramics exhibit relaxor properties and undergo on cooling a subsequent spontaneous macroscopic phase transition. The dielectric response is strongly affected by chemical (copper) doping and is found to become independent of the applied ac field for temperatures lower than the phase transition one.