TY - JOUR
T1 - Ferroelectric properties of vinylidene fluoride-trifluoroethylene copolymer thin films fabricated on amorphous alloy electrode
AU - Nakajima, Takashi
AU - Yamaura, Shin Ichi
AU - Furukawa, Takeo
AU - Okamura, Soichiro
N1 - Publisher Copyright:
© 2014 The Japan Society of Applied Physics.
PY - 2014/10/1
Y1 - 2014/10/1
N2 - We have investigated the structure and ferroelectric properties of vinylidene fluoride-trifluoroethylene (VDF-TrFE) copolymer thin films fabricated on amorphous alloy electrodes. Thin films of amorphous Pd-Cu-Si alloys with various compositions were successfully prepared by sputtering deposition. An atomically flat surface resulting from a fully amorphous structure of Pd-Cu-Si was obtained upon achieving a uniform surface of a spin-coated VDF-TrFE copolymer thin film. X-ray diffraction (XRD) measurements revealed that the crystalline structure of the VDF-TrFE copolymer thin films was of ferroelectric ß-phase, being independent of the composition and crystalline state of the Pd-Cu-Si alloy. The clearly observed D-E hysteresis loops showed a remanent polarization of 0.075C/m2 and a coercive field of 90MV/m at a measurement frequency of 10 Hz for a 50-nm-thick film, which is almost consistent with the results obtained with Pt electrode samples. We also observed the thinning-induced reduction of remanent polarization, which was explained by the depolarization field induced by the surface dead layer in VDF-TrFE copolymer rather than the oxidized layer in Pd-Cu-Si alloy electrode.
AB - We have investigated the structure and ferroelectric properties of vinylidene fluoride-trifluoroethylene (VDF-TrFE) copolymer thin films fabricated on amorphous alloy electrodes. Thin films of amorphous Pd-Cu-Si alloys with various compositions were successfully prepared by sputtering deposition. An atomically flat surface resulting from a fully amorphous structure of Pd-Cu-Si was obtained upon achieving a uniform surface of a spin-coated VDF-TrFE copolymer thin film. X-ray diffraction (XRD) measurements revealed that the crystalline structure of the VDF-TrFE copolymer thin films was of ferroelectric ß-phase, being independent of the composition and crystalline state of the Pd-Cu-Si alloy. The clearly observed D-E hysteresis loops showed a remanent polarization of 0.075C/m2 and a coercive field of 90MV/m at a measurement frequency of 10 Hz for a 50-nm-thick film, which is almost consistent with the results obtained with Pt electrode samples. We also observed the thinning-induced reduction of remanent polarization, which was explained by the depolarization field induced by the surface dead layer in VDF-TrFE copolymer rather than the oxidized layer in Pd-Cu-Si alloy electrode.
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U2 - 10.7567/JJAP.53.09PC05
DO - 10.7567/JJAP.53.09PC05
M3 - Article
AN - SCOPUS:84908108406
VL - 53
JO - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
JF - Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes
SN - 0021-4922
IS - 9
M1 - 09PC05
ER -