Influence of local strain heterogeneity on high piezoelectricity in 0.5Ba(Zr0.2Ti0.8)

Abstract

Hz and resonant ultrasound spectroscopy in the frequency range ~0.1-1.2 MHz confirm the existence of three phase transitions with falling temperature, at ~360 K (cubic-tetragonal), ~304 K (tetragonal-orthorhombic) and ~273 K (orthorhombic-rhombohedral). In comparison with BaTiO 3 , however, the transitions are marked by rounded rather than sharp minima in the shear modulus. The pattern of acoustic loss is also quite different from that shown by BaTiO 3 in having a broad interval of high loss at low temperatures, consistent with a spectrum of relaxation times for interactions of ferroelastic twin walls. Differences in the dielectric properties also suggest more relaxor-like characteristics for BZT-50BCT. It is proposed that the overall pattern of behavior is significantly influenced by strain heterogeneity at a local length scale in the perovskite structure due to the substitution of cations with different ionic 2 radii. The existence of this strain heterogeneity and its influence on the elastic behavior near the transition points could be contributory factors to the development of adaptive nanoscale microstructures and enhanced piezoelectric properties.

Local strain heterogeneity and elastic relaxation dynamics associated with relaxor behavior in the single-crystal perovskite Pb(In1/2NbHe1, Carpenter2, Lampronti3 et al. 2017Phys. Rev. BSelf Cite6030View full textAdd to dashboardCite

“…The overall pattern of a wide temperature interval of high loss is thus more typical of loss mechanisms with a wide spread of relaxation times, as seen for example in PbZr 0.53 Ti 0.47 O 3 −Pb(Fe 0.5 Ta 0.5 )O 3 [44], rather than of the single thermally activated process typical of twin-wall motion and freezing, as seen for example in KMnF 3 [45]. Schiemer et al [44] and Zhang et al [6] have attributed this spread to the presence of unit-cell scale-strain heterogeneity and, in the present study, the effect is larger for PIN-PZ-PMN-PT than for PMN-28PT.…”

“…These can have similar temperature dependences if the coupling between polarization and macroscopic strain is strong. On the other hand, the examples of PMN [35] and 0.5Ba(Zr 0.2 Ti 0.8 )O 3 −0.5(Ba 0.7 Ca 0.3 )TiO 3 [6] have shown that differences can be revealing of the nature of the relationship between strain and polarization on a local scale. Elastic compliance (1/f 2 ) and permittivity have therefore been plotted on the same graphs for PIN-PZ-PMN-PT and PMN-28PT in Figs.…”

“…Pb(In 1/2 Nb 1/2 )O 3 -PbZrO 3 -Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 represents one example of remarkable relaxor materials with high ferroelectric (FE) phase-transition temperature (T FE−FE > 120 • C) and excellent piezo-/dielectric properties (d * 33[001] > 1000 pm/V, ε 33[001] = 4000) [4,5]. The relaxor character is related to enhanced B-site disorder but, in the case of 0.5Ba(Zr 0.2 Ti 0.8 )O 3 -0.5(Ba 0.7 Ca 0.3 )TiO 3 , it has been shown that local strain heterogeneity influenced by the substitution of cations with different ionic radii in the ABO 3 perovskite structure acts as a major factor in the development of adaptive microstructures and the enhanced piezoelectric properties [6]. With respect to applications of piezoelectric and ferroelectric materials with dramatically improved temperature-insensitive properties, a key focus is therefore on the microstructures and strain-coupling effects as a function of temperature in Pb(In 1/2 Nb 1/2 )O 3 -PbZrO 3 -Pb(Mg 1/3 Nb 2/3 )O 3 -PbTiO 3 relaxor single crystal with decreasing length scale for the PNRs.…”

Phenomenological modeling of phase transitions and electrocaloric effect in Ba(Zr0.2Ti0.8)O3‐(Ba0.7Ca0.3)TiO3

“…The origin of high piezoelectricity has been explored based on experimental and theoretical studies, which suggest that perhaps several mechanisms work together to achieve the observed high performance. The following mechanisms have been proposed as origin for high piezoelectricity: flat‐free energy profile at the tricritical point, low polarization anisotropy energy, low energy barrier at the O‐T phase boundary, and large polarization fluctuation in the O phase .…”

On the high temperature phase transition in Ba(Zr0.20Ti0.80)O3ceramic

“…14 Investigations have been taken up world-wide with different aims on the solid solutions of BZT with other materials like: (Ba,Ca)TiO 3 , [15][16][17][18][19] (Bi 1=2 Na 1=2 ÞTiO 3 , [20][21][22][23] 29 NiO, 30 Ni, 31 polyvinyl alcohol, 32 epoxy, 33 Portland cement, 34,35 etc. Further, materials having high dielectric constant (10 3 -10 6 Þ are considered to be important nowadays keeping in view the growing interest in the fields of aeronautic, aerospace, power plants, automotive industries, oil and natural gas industries, various critical components' evaluation in nuclear industries, hybrid or electrically powered vehicles, thermal and geothermal engineering, etc.…”