In‐Plane Aligned Pb(Zr_xTi_1–x)O₃ Microbelts Fabricated by Near Migration and Restricted Growth

Abstract

Microelectromechanical systems (MEMS) and nanoelectromechanical systems (NEMS), which take advantage of wellestablished integrated-circuit manufacturing methods, continue to be an exciting multidisciplinary field with tremendous progress taking place in research and commercialization. The trend toward integration and miniaturization in MEMS and NEMS drives the development of interrelated smart materials such as ferroelectric and piezoelectric materials. Lead zirconate titanate (Pb[Zr x Ti 1±x ]O 3 , PZT) with outstanding piezoelectricity provides an excellent candidate as a smart material for use in MEMS and NEMS. Great efforts have therefore been taken to fabricate PZT micro-and nanostructures by downsizing existing PZT films using conventional microfabrication methods.[1] In the past decade since the discovery of carbon nanotubes, [2] the synthesis of one-dimensional (1D) materials has become the focus of intensive research because of their fundamental characteristics and potential applications. 1D micro-and nanomaterials with various microstructures, such as tubes, [3] belts, [4] wires, [5] and rods, [6] have been prepared by different synthetic routes. [7] For instance, a 1D zinc oxide nanostructure was extensively investigated for its dual semiconducting and piezoelectric properties.[4] Some scientists have attempted to fabricate 1D PZT microstructures by using unconventional methods based on physical or chemical synthesis to provide an alternative and intriguing strategy to overcome fundamental limitations of conventional microfabrication. For example, Wang et al. synthesized PZT fibers with diameters ranging from 500 nm to several micrometers using electrospinning and metallo-organic decomposition techniques.[8] By using sol±gel template electrophoresis synthesis methods, Limmer et al. prepared PZT nanorods with diameters of 70±150 nm and lengths of 10 lm.[9] However, in their methods there are some difficulties in assembly of the PZT fibers or rods for the construction of devices. In this paper, we propose the synthesis of self-assembled PZT microbelts by using a simple method. Long and thin PZT belt-type crystals, 50±150 lm long, 60±300 nm thick, and 1±2 lm wide, were prepared on SrTiO 3 (STO) monocrystal wafers with gold microparticles on the surface of the wafers. Details of the preparation procedure are given in the Experimental section. Figure 1 shows optical microscopy images of the PZT microbelts on STO(100) wafers, which were annealed at 930±970 C for 60 min in air. Well-aligned PZT microbelts with a width of 1±2 lm and a length of over 50 lm were grown on STO(100) substrates. The maximum length of the PZT microbelts reached 150 lm. Because of the limitations of optical microscopy, the microstructures of much finer PZT microbelts are not shown here. Figure 1A shows PZT microbelts annealed at a lower temperature (930 C). All the PZT microbelts developed along the <110> STO direction, being parallel with or perpendicular to each other. However, increasing the annealing temperature could interf...

One‐Dimensional Nanostructures of Ferroelectric Perovskites

“…In addition, physical deposition techniques such as magnetron sputtering and pulsed laser deposition have been used to deposit BaTiO 3 and PZT onto positive templates123 and PbZrO 3 in AAO templates 124. PZT stripes have been formed on SrTiO 3 substrates containing growth‐controlling gold particles by thermal evaporation 125…”

Piezoelectricity of lead-free (K, Na)NbO3 nanoscale single crystals

“…And it also makes KNN more attractive than PZT due to the complicated synthesis process of nanostructured PZT. 20 It is worth mentioning that exible and stretchable piezo-devices, which consist of nanoscale piezoelectric materials, are able to scavenge inappreciable energy effectively, such as rolling, bending, or even movement from human beings. 21 A high output electric signal from good piezoelectricity is required in such kind of energy harvesting applications, 10,22 and single crystalline KNN NRs would be the ideal choice.…”

Synthesis of highly piezoelectric lead-free (K, Na)NbO3 one-dimensional perovskite nanostructures

“…Traditional lead zirconate titanate (Pb(Zr, Ti)O 3 , PZT), one of the classical piezoelectric ceramics which is famous for high piezoelectric output, compromises its usefulness in many fields, such as biology, medicine and surgery, due to the toxic nature of the Pb element. [5][6][7][8][9][10] So the ideal material should be both highly piezoelectric-active and environmentally compatible, which promotes the newly developed (K, Na)NbO 3 (KNN) based lead-free perovskite as one of the most attractive candidates. 5,11,12 However, the challenge is synthesis and characterization of KNN materials at the nanoscale which may also be utilized to fabricate some other multifunctional composites.…”