Large Piezoelectric Response in Hybrid Rare-Earth Double Perovskite Relaxor Ferroelectrics

Abstract

Piezoelectric materials are technologically important, and the most used are perovskite ferroelectrics. In recent years, more and more emerging areas have put forward new requirements for piezoelectric materials, such as light weight, low acoustic impedance, good flexibility, and biocompatibility. In this context, hybrid organic–inorganic perovskite ferroelectrics have emerged as promising supplements, because they combine attractive features of inorganic and organic materials. Among them, hybrid double-metal perovskites have recently been found to exhibit excellent ferroelectricity. However, their potential as piezoelectric materials has not been exploited. Here, we describe large piezoelectric response in hybrid rare-earth double perovskite relaxor ferroelectrics (RM3HQ)2­RbLa­(NO3)6 and (RM3HQ)2­NH4La­(NO3)6 (RM3HQ = R-N-methyl-3-hydroxyl­quinuclidinium). They are simultaneously ferroelectric and ferroelastic crystals, with the R3 ferroelectric phase and P213 paraelectric phase. We found that ferroelectric polar microdomains and paraelectric nonpolar regions coexist in a wide temperature range through variable-temperature piezoresponse force microscopy images. The two-phase coexistence reveals low energy barriers of transitions between the two phases and between the polar microdomains with different polarization directions. These lead to the easy polarization rotation of the polar microdomains upon applying a stress and, accordingly, the large piezoelectric response up to 106 pC N–1 for (RM3HQ)2­RbLa­(NO3)6. This finding represents a significant step toward novel applications of piezoelectric materials based on lead-free hybrid perovskites.

Organic Enantiomeric Ferroelectrics with High Piezoelectric Performance: Imidazolium l- and d-Camphorsulfonate

“…Besides, we also used the PFM measurement to evaluate the piezoelectric performance of L-ImCS on its single crystal along the b-axis. 61 As shown in Figure 5d, good linearity is proof of the piezoelectric effect. Taking PVDF (28 pC N −1 ) as a benchmark, the local piezoelectric coefficients of crystal L-ImCS were evaluated to be 15.8 pC N −1 , comparable to that of TGS.…”

“…This confirms the 222F2-type ferroelectrics, which exhibits a uniaxial feature. Besides, we also used the PFM measurement to evaluate the piezoelectric performance of l -ImCS on its single crystal along the b -axis . As shown in Figure d, good linearity is proof of the piezoelectric effect.…”

Synthesis Attempt and Structural Studies of Novel A2CeWO6 Double Perovskites (A2+ = Ba, Ca) in and outside of Ambient Conditions

“… 19 , 30 Adjustable conductivity 31 and eventual photocatalytic properties are also within grasping range. 32 − 34 In general, these materials have gained great technological interest as dielectrics 35 − 37 or piezoelectric sensors, 8 , 38 , 39 magnetic memory components, 13 electrodes, and media for well-developed fuel- 40 − 42 or solar cells. 43 − 45 But this is a topic for a separate discussion and will not be divulged here further.…”

The construction of a two-dimensional organic–inorganic hybrid double perovskite ferroelastic with a high Tc and narrow band gap

“…Here, the B I -site cation mainly includes alkali metal and group IB elements, and the B III -site cation are abundant elements that can locate at group B and group A, and the X at corner can contain halogen, CN − and NO 3− . 28–36 As a member of double perovskites, two-dimensional double perovskites with a formula of A 4 B I B III X 8 show multiple fascinating properties, such as ferroelectricity, 37–39 piezoelectricity, 39 X-ray detection, 40–42 light response, 35,36,43 broad photoluminescence, 44 phase transition 38 and so on, 45 which inspire us to grope new 2D double perovskites with desired properties in lead-free exploration.…”