There has been much interest in recent years in improving Direct Current Poling (DCP) for piezoelectric materials. Some of the more promising substitutes include Alternating Current Poling (ACP), Water Quench Poling (WQP), and ACP with Field Cooling (ACP-FC). This paper summarizes the merits of these poling strategies and compares them to pulse poling. The results show that pulse poling outpaces both DCP and ACP in terms of the magnitude of piezoelectric response across a range of materials. Hard and soft piezoelectric samples in both single crystal and textured form were poled using all these techniques. For the single crystal samples (with compositions of Mn: Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIN–PMN–PT) and Sm: PIN–PMN–PT), pulse poling generated the greatest increase in d33 and keff relative to DCP, with both piezoelectrics seeing increases above 65%. In the case of the {001} textured Mn: PMN–PZT–PT material, pulse poling and ACP-FC reduced the loss of the system and improved its mechanical quality factor (Qm) by 20% and 4%, respectively. These phenomena were further investigated via Rayleigh analysis to quantify each poling strategy’s impact on domain wall dynamics. The textured ceramic samples showed lower overall values of α (which is related to the mobility and concentration of domain walls) when compared to the single crystals. It was found that α decreased for the unconventionally poled textured samples relative to DCP, whereas the single crystals’ α values increased. Samples that underwent WQP experienced significant microcracking, limiting possible applications.
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Ferroelectric Domain Wall Engineering Enables Thermal Modulation in PMN–PT Single Crystals
Acting like thermal resistances, ferroelectric domain walls can be manipulated to realize dynamic modulation of thermal conductivity (k), which is essential for developing novel phononic circuits. Despite the interest, little attention has been paid to achieving room-temperature thermal modulation in bulk materials due to challenges in obtaining a high thermal conductivity switching ratio (khigh/klow), particularly in commercially viable materials. Here, room-temperature thermal modulation in 2.5 mm-thick Pb(Mg1/3Nb2/3)O3–xPbTiO3 (PMN–xPT) single crystals is demonstrated. With the use of advanced poling conditions, assisted by the systematic study on composition and orientation dependence of PMN–xPT, a range of thermal conductivity switching ratios with a maximum of ≈1.27 is observed. Simultaneous measurements of piezoelectric coefficient (d33) to characterize the poling state, domain wall density using polarized light microscopy (PLM), and birefringence change using quantitative PLM reveal that compared to the unpoled state, the domain wall density at intermediate poling states (0< d33
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- Award ID(s):
- 2011978
- PAR ID:
- 10410200
- Date Published:
- Journal Name:
- Advanced Materials
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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