Re‐entrant relaxor behavior in BaTiO₃‐Bi(Zn_2/3Nb_1/3)O₃ ceramics

Abstract

The (1−x)BaTiO3−xBi(Zn2/3Nb1/3)O3 (x=0.10‐0.25) ceramics were fabricated via solid‐state reactions. Temperature‐dependent polarization measurement reveals that with the temperature lowering, the remnant polarization increases till a maximum value before it decreases, showing a reentrant phenomenon. Absence of apparent switching current peaks in the current density as a function of electric field should indicate the lack of a ferroelectric transition, which is further verified by the consistent macroscopic phase structure from the Raman spectra. An anomalous peak in the full width at half maximum of a deconvoluted mode at ~515 cm−1 suggests the entering of a more disordered state of dipolar dynamics, which may be originated from the competition between the freezing of polar nanoregions and the random interacting fields.

Re‐entrant dipole glass‐like behavior and lattice dynamics of 0.65Bi(Mg1/2Ti1/2)O3‐0.35PbTiO3

“…Interestingly, an anomalous peak was found at 348 K in Figure , which is also consistent with the inherent re‐entrant temperature determined from the imaginary part of the dielectric constant (Figure B). Consequently, this anomalous peak should confirm that with decreasing temperature, the PNRs (formed by clustering of B‐site ions) in the system enters a more disordered state . Meanwhile, the broad Raman peak is related to microscopic chemical heterogeneity due to the difference in ionic size, valence, and electronegativity of B‐site ions .…”

“…1,2 It is reported that a re-entrant relaxor behavior is presented in BaTiO 3 -BiScO 3 , BaTiO 3 -Bi(Zn 2/3 Nb 1/3 )O 3 , and (K 0.5 Na 0.5 ) NbO 3 -(Na 1/2 Bi 1/2 )TiO 3 . [3][4][5] Meanwhile, the similar behaviors have been reported in Pb/Bi-based perovskites, such as (Ba 0.925 Bi 0.05 )(Ti 1-x/100 Sn x/100 )O 3 and Pb 0.76 Ca 0.24 TiO 3.…”

“…Consequently, this anomalous peak should confirm that with decreasing temperature, the PNRs (formed by clustering of B-site ions) in the system enters a more disordered state. 4 Meanwhile, the broad Raman peak is related to microscopic chemical heterogeneity due to the difference in ionic size, valence, and electronegativity of B-site ions. 16 Therefore, the off-centered Bi 3+ ion and weakening Ti-O bond could result in the present polar clusters.…”

Effect of A‐site substitutions on energy storage properties of BaTiO3‐BiScO3 weakly coupled relaxor ferroelectrics

“…Following such initial success, solid solutions with more complex Me substitutions on the B site were also explored for potential improvements in dielectric properties. Examples include BaTiO 3 ‐Bi(Zn 1/2 Ti 1/2 )O 3 , BaTiO 3 ‐Bi(Zn 2/3 Nb 1/3 )O 3 , BaTiO 3 ‐Bi(Mg 2/3 Nb 1/3 )O 3 , and BaTiO 3 ‐Bi(Zn 1/2 Ti 1/2 )O 3 ‐BiScO 3 . The incorporation of additional Me ions is presumed to enhance the net atomic displacements at the B site, thereby giving rise to higher electrical dipole moments and therefore larger k .…”

“…Following such initial success, solid solutions with more complex Me substitutions on the B site were also explored for potential improvements in dielectric properties. Examples include BaTiO 3 [7][8][9][10][11][12][13] The incorporation of additional Me ions is presumed to enhance the net atomic displacements at the B site, thereby giving rise to higher electrical dipole moments and therefore larger k. While some promising trends are indeed observed for the above listed dielectric ceramics, they nevertheless face several shortcomings. The frequency-independent response of (1-x) BaTiO 3 -xBiMeO 3 dielectrics are observed only above 150°C.…”