Control of specific domain structure in KNbO3 single crystals by differential vector poling method

Abstract

The controllability of specific domain structures in KNbO3 single crystals was investigated by electric poling to several different orientations at room temperature. By applying electric field to the direction corresponding to the differetial direction between the original and intended spontaneous polarization directions (differential vector poling method), 60°-, 90°-, and 180°-domain pairs were successfully fabricated under control in KNbO3. The measured threshold electric field for 90°-domain pairs was the lowest (140V∕mm), which could be related to the difference between the piezoelectric coefficients of the poling direction. For 60°- and 90°-domain pairs, theoretical uncharged domain walls fabricated under control without the generation of other domain structures. For 120°-domain pairs, (011)pc uncharged domain wall was not observed, which suggests the difficulty in generating uncharged 120°-domain walls without passing through the phase transition.

Microstructural origin for the piezoelectricity evolution in (K0.5Na0.5)NbO3-based lead-free ceramics

“…34,35 Four essentially different domain walls with spontaneous polarization (P s ) subtending angles of 60 , 90 , 120 and 180 can be adopted in the orthorhombic phase, while only 90 and 180 types exist in the tetragonal phase. These ferroelectric domain walls are limited to {100} planes for orthorhombic 90 domains and {110} for both orthorhombic 120 and tetragonal 90 domains.…”

Polarization alignment, phase transition, and piezoelectricity development in polycrystalline0.5Ba(Zr0.2Ti0.8)O3−Guo1, Voas2, Zhang3 et al. 2014Phys. Rev. B806360View full textAdd to dashboardCite

“…Also, the capacitance of a virgin disk sample was measured at 1 kHz under the same dc bias conditions. The piezoelectric coefficient d 33 and elastic compliance constants s D 33 and s E 33 were then calculated. Another bar-shaped specimen was poled at room temperature with a dc field of 20 kV/cm from its virgin state.…”

“…Another bar-shaped specimen was poled at room temperature with a dc field of 20 kV/cm from its virgin state. It was then allowed to age at room temperature for 5 days, and the d 33 and s E 33 were measured during the repoling process following the same procedure described above.…”

“…Among the most studied lead-free solid solutions, Ba(Zr 0.2 Ti 0.8 )O 3 -(Ba 0.7 Ca 0.3 )TiO 3 (BZT-BCT) stands out for its exceptionally high piezoelectric properties. Specifically, a piezoelectric coefficient d 33 as high as 620 pC/N has been observed in polycrystalline 0.5Ba(Zr 0.2 Ti 0.8 )O 3 -0.5(Ba 0.7 Ca 0.3 )TiO 3 (50BZT-50BCT) [3]. Similar to Pb(Zr,Ti)O 3 , the BZT-BCT solid solution crystallizes in three perovskite phases: paraelectric cubic (P m3m), ferroelectric rhombohedral (R3m), and ferroelectric tetragonal (P 4mm) [3].…”

Unique single-domain state in a polycrystalline ferroelectric ceramic

“…(2) The grains in the ceramic are typically in a size above 10 μm [23]. An orientation dependence of the poling response is expected, as in single crystals of other ferroelectric perovskites [24].…”