Influence of B-site chemical ordering on the dielectric response of the Pb(Sc_1/2Nb_1/2)O₃relaxor

Abstract

The influence of chemical B-site ordering between Sc 3+ and Nb 5+ cations on the properties of the Pb(Sc 1/2 Nb 1/2)O 3 (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 Sc 3+ and Nb 5+ 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 to lower temperature owing to the presence of the ordered phase. Moreover, an additional short-range structural ordering is shown to exist in disordered PSN. This additional ordering, for which antiparallel displacements of Pb atoms could be involved, is favoured by chemical ordering between Sc 3+ and Nb 5+ and is long range in ordered PSN.

Effect of Ni doping on ferroelectric and dielectric properties of strontium barium niobate crystals

“…It was reported that the Curie temperature for a ferroelectric transition depends on the material composition [33,34]. Our results obtained for highly defected crystals may confirm that the compositional disorder could play an important role on the ferroelectric phase transition diffuseness and the low frequency dielectric response.…”

Relationship between Local Structure and Relaxor Behavior in Perovskite Oxides

“…Using Eq. (5), we obtain T disp values of 0 and 15 K for ordered and disordered PSN, respectively, in agreement with experimentally observed T disp values of 0 -8 and 8-12 K for annealed and as-sintered PSN samples, respectively [33][34][35][36][37]. For PST, using Eq.…”

Classical ferroelectriclike behavior of highly orderedPb(Sc1/2Nb1/2Sivasubramanian1, Subramanian2, Kojima3 2016Phys. Rev. B7150View full textAdd to dashboardCite

“…For the completely ordered PSN, the theoretical intensity ratio I 111 /I 200 is 0.09 [36]. The degree of the B site ordering of the as-grown single crystal was determined to be S = 0.80.…”