Strengthened relaxor behavior in (1−x)Pb(Fe_0.5Nb_0.5)O₃–xBiFeO₃

Abstract

A systematic study of (1−x)Pb(Fe0.5Nb0.5)O3–xBiFeO3 (x = 0–0.5) was performed in order to investigate the strengthening of the relaxor properties when adding BiFeO3 into Pb(Fe0.5Nb0.5)O3 and forming a solid solution.

Pb(Fe0.5Nb0.5)O3–BiFeO3-based multicalorics with room-temperature ferroic anomalies

“…A reason for the progressively increased relaxor behavior by the addition of BFO is most probably related to the increased compositional disorder at the A-site of the perovskite structure, which arises when different multivalence ions occupy a crystalographically equivalent place in the crystal lattice. 42,51,52 Heterovalent substitution of the differently sized Pb 2+ (119 pm) 53 and Bi 3+ (103 pm) 53 ions appears to disturb a long-range ferroelectric order in PFN-rich PFN-BFO solid solutions as previously suggested for Pb-based relaxors. 54 In the next step, the influence of BFO addition on the magnetic properties of PFN-100xBFO was studied.…”

“…1b and reported in ref. 42. By further increasing the BFO content (x Z 0.3), the peak-permittivity temperature seemingly shifts to temperatures above the one of PFN (i.e., 113 1C), as visible from e 0 measurements at 100 kHz (inset of Fig.…”

“…All prepared ceramics were singlephase, homogeneous and highly dense (497.6% of the crystallographic density), as previously reported in ref. 42. The temperature dependences of the real component of the relative permittivity e 0 for all compositions measured at 1 kHz are shown in Fig.…”

“…The preparation process of unmodified PFN-100xBFO powders is described in detail in our previous work. 23,42 The same synthesis procedure was employed also for Mn-doped PFN-20BFO, where 0.5 mol% of Mn in the form of MnO 2 (99.9%, Alfa Aesar) were added to the mixture of initial oxides as a substitution for B-site cations (Fe 3+ and Nb 5+ ) according to the nominal formula 0.8Pb(Fe 0.5 Nb 0.5 ) 0.995 Mn 0.005 -O 3 -0.2BiFe 0.995 Mn 0.005 O 3 . MnO 2 was pre-milled in an attrition mill (Netzsch, PE075/PR01, Selb, Germany) with absolute ethanol at 600 min À1 for 5 h using yttria-stabilized zirconia (YSZ) milling balls (ball diameter, 3 mm).…”

“…45 and used in our previous work. 23,42 The use of the saturated oxygen atmosphere during the sintering prevents (or minimizes) the reduction of Fe 3+ to Fe 2+ and reduces the amount of oxygen vacancies, which consequently resulted in a lower electrical conductivity and dielectric losses of the material. 45 For all samples, a heating and cooling rate of 2 1C min À1 was used.…”