Lead-Free Ferroelectric Thin Films

Abstract

Sol-gel-derived ferroelectric thin films, with lead zirconate titanate (Pb(Zr,Ti)O 3 , PZT) as one of the most widely studied materials, have been investigated for a wide range of applications, including microelectromechanical systems. The research of environment-friendly alternatives to lead-based materials, to a large extent driven by legislation, has been mainly conducted in the domain of bulk ceramics; however, environment-friendly alternatives to lead-based ferroelectric

Comparative Solution Synthesis of Mn Doped (Na,K)NbO3 Thin Films

“…The final molarity of the solution was 0.4 M. The solution was aged in a refrigerator for one week, following recommendations in the literature [54]. This preparation method was inspired by work of Kupec et al and Ahn et al [3,13,20].…”

“…Solution methods for KNN deposition are categorized according to the starting alkali precursors into acetate based (11,13,14,18,(20)(21)(22)(23) and alkoxide based (15,16,(24)(25)(26)(27)(28)(29)(30) approaches. In both cases, niobium ethoxide is usually employed as the Nb precursor and 2-MOE or 1,3 propanediol as solvents [31,18].…”

“…Nonetheless, the functional properties of KNN films are interesting for piezoMEMS applications. The relative permittivity for undoped KNN films prepared by either acetate and alkoxide based routes was reported to range from 490 to 725 with dielectric loss ranging from 1.5 to 8% at 1 kHz [13,14,16,20]. Lee et al reported relative permittivity values as high as 1050 for 0.5 Mn mol% doped KNN films made via an acetate route.…”

Epitaxial K 0.5 Na 0.5 NbO 3 thin films by aqueous chemical solution deposition

“…A number of lead-free piezoelectric polycrystalline materials have been developed and, among them, potassium sodium niobate K x Na 1−x NbO 3 (KNN) shows a potential for the replacement of the high performance PZT-based materials, especially if the piezoelectric performance is enhanced by texturing [1–4]. Moreover, the use of highly oriented thin films of KNN-based compositions is promising for microelectromechanical applications [3,5]. KNN-based thin films have been grown by various physical methods such as pulsed laser deposition [6], radio frequency magnetron sputtering [7], metal-organic chemical vapour deposition [8] and atomic layer deposition [9].…”

Controlling Phase Purity and Texture of K0.5Na0.5NbO3 Thin Films by Aqueous Chemical Solution Deposition

“…The ferroelectric performance of thin films is strongly correlated with the microstructure. Of special interest is the ability to tailor the degree of texturing in ferroelectric thin films, since the ferroelectric performance is coupled directly to the microstructural orientation [27]. Both polycrystalline and epitaxial KNN thin films have been prepared by CSD by tailoring the thermal processing to favor either homogeneous or heterogeneous nucleation, respectively [25].…”