Phase transitions and optical characterization of lead-free piezoelectric (K0.5Na0.5)0.96Li0.04(Nb 0.8Ta0.2)O3 thin films
Type
ArticleKAUST Department
Imaging and Characterization Core LabAdvanced Nanofabrication, Imaging and Characterization Core Lab
Core Labs
Date
2013-06Permanent link to this record
http://hdl.handle.net/10754/562794
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Lead-free piezoelectric thin films, (K0.5Na0.5) 0.96Li0.04(Nb0.8Ta0.2)O 3, were epitaxially grown on MgO(001) and Nb-doped SrTiO 3(001) substrates using pulsed laser deposition. The optimum deposition temperature was found to be 600 C. Two types of in-plane orientations were observed in the films depending on the substrates used. The transmittance and photoluminescence spectra as well as the dielectric and ferroelectric properties of the films were measured. The measured band-gap energy was found to be decreased with the deposition temperature. The dielectric constant decreased from 550 to 300 as the frequency increased from 100 Hz to 1 MHz. The measured remnant polarization and coercive field were 4 μC/cm2 and 68 kV/cm, respectively. The phase transitions of the films were studied by Raman spectroscopy. Two distinct anomalies originating from the cubic-to-tetragonal (TC-T ~ 300 C) and tetragonal-to-orthorhombic (TT-O ~ 120 C) phase transitions were observed. Our results show that Raman spectroscopy is a powerful tool in identifying the phase transitions in ferroelectric thin films. © 2013 Elsevier B.V.Citation
Yao, Y. B., Chan, H. T., Mak, C. L., & Wong, K. H. (2013). Phase transitions and optical characterization of lead-free piezoelectric (K0.5Na0.5)0.96Li0.04(Nb0.8Ta0.2)O3 thin films. Thin Solid Films, 537, 156–162. doi:10.1016/j.tsf.2013.04.043Sponsors
This research was supported by a research grant of the Hong Kong Polytechnic University (GU693).Publisher
Elsevier BVJournal
Thin Solid Filmsae974a485f413a2113503eed53cd6c53
10.1016/j.tsf.2013.04.043