Polarization relaxation anisotropy in Pb(Zn1/3Nb2/3)O3-PbTiO3 single-crystal ferroelectrics as a function of fatigue history

Abstract

Polarization relaxation was studied in Pb(Zn1/3Nb2/3)O3-PbTiO3 (PZN-PT) single crystals that show fatigue anisotropy. To excite prepoled crystals, a modest dc voltage (<1/2 of the coercive field) was applied along the poling direction. Upon removal of the voltage, the polarization decay in the time domain was measured. Experimental data were modeled with a stretched exponential function. Stretching exponent (β〈hkl〉) and characteristic time (τ〈hkl〉) constants for polarization relaxation were determined from data over four decades in the time domain at different stages of bipolar cycling. β〈hkl〉 values after 101 cycles were 0.146±0.002 and 0.247±0.0004 in the 〈001〉 and 〈111〉 orientations, respectively. The β〈111〉 constant increased up to 0.453±0.104 after 105 cycles in 〈111〉 oriented crystals that show fatigue. However, much less change is observed in β〈001〉 as a function of cycling for 〈001〉 crystals. Characteristic time constants for relaxation (τ〈hkl〉) were calculated for 〈001〉 and 〈111〉 orientations as 0.401±0.048 s and 57.46±0.10 s, respectively. These results suggest a faster polarization relaxation in 〈001〉 than in the 〈111〉 orientation of rhombohedral PZN-PT ferroelectric crystals.

Large Piezoelectric Strain with Superior Thermal Stability and Excellent Fatigue Resistance of Lead-Free Potassium Sodium Niobate-Based Grain Orientation-Controlled Ceramics

“…There are two major ways to improve the fatigue endurance of piezoelectricity. The first one is to keep the ceramic away from the MPB or PPT, which is not viable because it will result in a huge decrease in the piezoelectric response. , Furthermore, some previous works reported that ⟨001⟩ c -oriented rhombohedral ferroelectric materials show excellent fatigue resistance, whereas ⟨111⟩ c -oriented rhombohedral ferroelectric materials demonstrate a much poorer fatigue resistance. − Therefore, for the piezoelectric materials with coexisting tetragonal–rhombohedral phases, the alternative approach is to control their orientation.…”

Effect of internal bias field on domain switching in (CH3NH3)5Bi2Br11 crystal

“…The results indicate that no significant difference exists in the polarization relaxation behavior of bulk material and that observed in thin films. 29,30 Similar to the thin films, in the bulk MAPBB crystal an initial drop of the polarization is observed which then levels out to a slow decrease, fitted by a stretched-exponential function.…”