Positive temperature coefficient of resistivity in Pb(Fe 1/2 Nb 1/2 )O 3 ceramics

Structure and Dynamics of Ferroelectric Domains in Polycrystalline Pb(Fe1/2Nb1/2)O3

“…They can be further divided into two subgroups, either with flat or with curved domain walls (DWs), as demonstrated in Figure 3b. Both types of domains were already observed in the polycrystalline samples [10], while only curved DWs were detected in the single crystals [12]. Such wedge-type domains have previously been observed in some ferroelectric materials with a monoclinic structure [24,25].…”

“…The first type is the wedge domains that were already observed, in both cases by TEM, in PFN polycrystalline samples [10] and single crystals [12]. In the former, the authors observed only wedge-like domains, while in the latter the wedge-shaped domains coexist with tweeds.…”

“…However, the ferroelectric domains and their switching were not yet revealed. Until now, only one transmission electron microscopy (TEM) image showing wedge-shaped domains a few hundred nanometres in size [10] had been reported.…”

Phase evolution, dielectric and impedance spectroscopic study of SrNb2O6 columbite phase

“…Because of lack of experimental data in the higher frequency and temperature regions, we are unable to describe the resistive behavior of the compound. Above 100 8C, resistivity of the compound increases may be due to resulted in a superimposition of the two elements (grain and grain boundary) as temperature increased [19].…”

Anisotropic Colossal Dielectric Response of 0.93Pb(Fe1/2Nb1/2)O3–0.07PbTiO3 Single Crystals along [100] and [111] Directions

“…9,10) PFN is rhombohedral at room temperature and undergoes ferroelectric-paraelectric and rhombohedral-cubic phase transitions at a Curie temperature (T C ) of 385 11) or 383 K. 12) It also exhibits a long-range antiferromagnetic order below the Nee ´l temperature T N $ 143 K. 13) Lee et al observed a high dielectric constant ($10 4 ) in PFN ceramics, which was supposed to be due to the relaxation of grains and grain boundaries. 14) Pb(Fe 1=2 Nb 1=2 )O 3 -PbTiO 3 (PFNT), a modified multiferroic material based on PFN, has also been studied intensively in recent years. Although some works on the CDC behavior have been reported for PFNT ceramics and single crystals, 15,16) to our knowledge, the anisotropic dielectric properties of PFNT single crystals have not yet been reported.…”