Crystal structure and local piezoelectric properties of strain-controlled (001) BiFeO3 epitaxial thin films

Ujimoto, Katsuya; Yoshimura, Takeshi; Wakazono, Keisuke; Ashida, Atsushi; Fujimura, Norifumi

doi:10.1016/j.tsf.2013.10.178

Cited by 10 publications

(6 citation statements)

References 26 publications

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“…The toxicity of lead in Pb(Zr,Ti)O 3 (PZT)-based thin films affects the natural environment and the human body, hence, the development of lead-free piezoelectric thin films has recently become a necessity. Bismuth layer-structured piezoelectrics, BaTiO 3 , (K,Na)NbO 3 (KNN), (Bi,Na,K)TiO 3 , and BiFeO 3 [1][2][3][4][5][6][7][8][9][10] have been investigated as candidate materials for lead-free piezoelectric thin films. However, to use lead-free piezoelectric materials in microelectromechanical systems (MEMS), [11][12][13] lead-free piezoelectric thin films grown on Si substrates must have a high piezoelectric coefficient and a low dielectric constant.…”

Section: Introductionmentioning

confidence: 99%

Annealing effects on epitaxial (K,Na)NbO₃ thin films grown on Si substrates

Tanaka

Ogawa

Kweon

et al. 2022

Jpn. J. Appl. Phys.

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Epitaxial (K,Na)NbO3 (KNN) thin films were deposited on (001)SrRuO3/Pt/ZrO2/Si substrates by RF magnetron sputtering and their post-annealing effects for the as-deposited epitaxial KNN thin films were investigated. By the annealing, the crystal system changed from tetragonal to orthorhombic system due to the release of the internal stress. Asymmetry of the polarization-electric field (P–E) hysteresis loops along the electric field were changed from positive to negative side by the annealing. It represents that stable spontaneous polarization P s was changed from upward to downward direction induced by increasing of A-site vacancies. The displacement-electric field (D–E) curves of the epitaxial KNN/Si unimorph cantilevers also showed asymmetric behaviors. Relatively high converse piezoelectric coefficient |e 31,f | = 6.4 C/m2 was obtained from the 5 h-annealed epitaxial KNN thin films.

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Section: Introductionmentioning

confidence: 99%

Annealing effects on epitaxial (K,Na)NbO₃ thin films grown on Si substrates

Tanaka

Ogawa

Kweon

et al. 2022

Jpn. J. Appl. Phys.

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“…19) We have also improved the piezoelectric properties of BiFeO 3 films by domain engineering and by using strain-induced morphotropic phase boundary (MPB). 20,21) The highest e 31; f coefficient of a domain-engineered BiFeO 3 film to date, reported in Ref. 21, is À4:3 C/m 2 .…”

mentioning

confidence: 96%

“…20,21) The highest e 31; f coefficient of a domain-engineered BiFeO 3 film to date, reported in Ref. 21, is À4:3 C/m 2 . Although the e 31; f coefficient is lower than that in polycrystalline PZT films, the energy conversion FOM of the BiFeO 3 film is as high as 20.8 GPa, which is comparable to those of the best-performing PZT films.…”

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confidence: 96%

Piezoelectric Vibrational Energy Harvester Using Lead-Free Ferroelectric BiFeO₃Films

Yoshimura¹,

Murakami²,

Wakazono³

et al. 2013

Appl. Phys. Express

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We have proposed that BiFeO3 films are suitable for piezoelectric vibrational energy harvester (VEH) applications, because BiFeO3 has high spontaneous polarization and low dielectric permittivity. We demonstrated that energy can be harvested by a micromachined VEH using a BiFeO3 film deposited using a sol–gel process. A VEH with a resonant frequency of ∼98 Hz produced an output voltage of 1.5 V·G-1 and electrical power of 2.8 µW·mm-3·G-2 (G=9.8 m/s2) at a load resistance of 1 MΩ. Using the analytical model for VEH, the generalized electromechanical coupling factor was estimated to be 0.41%. These results were comparable to those of the best-performing VEHs using other piezoelectric films.

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“…Therefore, efforts to mitigate the environmental impact of piezoelectric devices that contain lead-based piezoelectric materials have led to the development of lead-free piezoelectric materials. Several candidates for lead-free piezoelectric materials have been investigated for use in thin-film devices, including BiFeO 3 (BFO), − AlN, − and (K,Na)NbO 3 (KNN). − Among these materials, KNN is the most promising because of its high Curie temperature and good piezoelectric properties. Numerous researchers have reported that KNN thin films exhibit strong piezoelectric properties, and piezoelectric energy harvesters with KNN thin films have an output power comparable to that of harvesters with PZT thin films. , However, the origin of the strong piezoelectric properties of KNN thin films remains unclear because crystallographic deformation by piezoelectric effects is not yet understood in detail.…”

Section: Introductionmentioning

confidence: 99%

In Situ XRD Observation of Crystal Deformation of Piezoelectric (K,Na)NbO₃ Thin Films

Tan

Kweon

Shibata

et al. 2020

ACS Appl. Electron. Mater.

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Metrics & MoreArticle Recommendations * sı Supporting Information ABSTRACT: (K,Na)NbO 3 (KNN) thin films are promising lead-free piezoelectric materials for microelectromechanical systems (MEMS) devices. However, the origin of the strong piezoelectric properties of KNN thin films remains unclear because crystallographic deformation by piezoelectric effects is not clear in detail. We used synchrotron X-ray diffraction (XRD) to explore the origin of the piezoelectricity of polycrystalline (K 0.45 Na 0.55 )NbO 3 (KNN) thin films, which led to the observation of large crystal deformation originating from the piezoelectric effects. The peak shifts of the XRD patterns indicated changes in both the out-of-plane and in-plane lattice parameters of KNN.In addition, an electric field-induced phase transition under an applied electric field was observed. The microscopic piezoelectric coefficients (e 31,f ) were estimated from the in situ XRD results and subsequently compared with the macroscopic piezoelectric coefficients estimated from the converse piezoelectric effect by the cantilever method. The macroscopic |e 31,f | coefficients based on the converse piezoelectric effect were in the range of 6.3−11.1 C/m 2 , whereas the microscopic |e 31,f | values based on the in situ XRD results were in the range of 1.2−1.5 C/m 2 . However, the macroscopic piezoelectric coefficients from the direct piezoelectric effect were 1.6−2.0 C/m 2 , which were similar to those obtained from the in situ XRD results. The results suggest that the large macroscopic piezoelectric properties associated with the converse piezoelectric effect arise from the observed electric field-induced phase transition. This study demonstrates the main factors associated with the macroscopic piezoelectric properties in lead-free KNN thin films.

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Crystal structure and local piezoelectric properties of strain-controlled (001) BiFeO3 epitaxial thin films

Cited by 10 publications

References 26 publications

Annealing effects on epitaxial (K,Na)NbO₃ thin films grown on Si substrates

Annealing effects on epitaxial (K,Na)NbO₃ thin films grown on Si substrates

Piezoelectric Vibrational Energy Harvester Using Lead-Free Ferroelectric BiFeO₃Films

In Situ XRD Observation of Crystal Deformation of Piezoelectric (K,Na)NbO₃ Thin Films

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Crystal structure and local piezoelectric properties of strain-controlled (001) BiFeO3 epitaxial thin films

Cited by 10 publications

References 26 publications

Annealing effects on epitaxial (K,Na)NbO3 thin films grown on Si substrates

Annealing effects on epitaxial (K,Na)NbO3 thin films grown on Si substrates

Piezoelectric Vibrational Energy Harvester Using Lead-Free Ferroelectric BiFeO3Films

In Situ XRD Observation of Crystal Deformation of Piezoelectric (K,Na)NbO3 Thin Films

Contact Info

Product

Resources

About

Annealing effects on epitaxial (K,Na)NbO₃ thin films grown on Si substrates

Annealing effects on epitaxial (K,Na)NbO₃ thin films grown on Si substrates

Piezoelectric Vibrational Energy Harvester Using Lead-Free Ferroelectric BiFeO₃Films

In Situ XRD Observation of Crystal Deformation of Piezoelectric (K,Na)NbO₃ Thin Films