Raman Spectroscopy of Ferroelectric Thin Films

ABSTRACTDuring a ferroelectric phase transition or domain rearrangement, ions or molecules in a ferroelectric material move in a highly cooperative manner from their initial lattice positions into the final positions they occupy and the collective response results into a “soft” lattice vibrational mode. Moreover, the structural changes are always accompanied by at least a few other changes in the normal mode behavior of the material. In the present work, Raman spectroscopy is conveniently employed to study such vibrational modes and other related phenomena in ferroelectric materials at the sub-microscale levels. We have investigated ferroelectric thin films of various lead and barium based perovskites prepared by sol-gel technique. The effect of processing conditions, A- and B- site substitutions, and size dependence on their Raman spectra were analyzed in terms of the structure-property correlations.

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Electrical Properties of Amorphous Thin Films of Ferroelectric Oxides Prepared by Sol-Gel Technique

MRS Proceedings ◽

10.1557/proc-310-441 ◽

1993 ◽

Vol 310 ◽

Cited By ~ 1

Author(s):

Yuhuan Xu ◽

Ren Xu ◽

Chih-Hsing Cheng ◽

John D. Mackenzie

Keyword(s):

Thin Films ◽

Electrical Properties ◽

Lead Zirconate Titanate ◽

Sol Gel ◽

Lead Zirconate ◽

Ferroelectric Thin Films ◽

Amorphous Thin Films ◽

Crystalline Films ◽

Gel Technique ◽

Ferroelectric Oxides

AbstractAmorphous thin films of ferroelectric oxides including lead zirconate titanate (PZT), barium titanate (BaTiO3) and lithium niobate (LiNbO3) on several kinds of substrates were prepared by a sol-gel technique. The heat-treatment temperatures for preparation of amorphous thin films were much lower than those for the corresponding crystalline ferroelectric thin films. Electrical properties of these amorphous thin films were measured and compared with those of corresponding crystalline films. These amorphous thin films exhibited ferroelectric-like behavior. A model of the microstructure of these films is proposed.

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Ferroelectric Thin Films by sol-gel Processing

MRS Proceedings ◽

10.1557/proc-152-227 ◽

1989 ◽

Vol 152 ◽

Cited By ~ 23

Author(s):

S. L. Swartz ◽

P. J. Melling ◽

C. S. Grant

Keyword(s):

Thin Films ◽

Single Crystal ◽

Sol Gel ◽

Fused Silica ◽

Ferroelectric Materials ◽

Ferroelectric Thin Films ◽

Silicon Substrates ◽

Heat Treated ◽

Pzt Films ◽

Gel Processing

ABSTRACTThe sol-gel processing of ferroelectric thin films is being investigated at Battelle. The ferroelectric materials included in this study are PbTiO3, Pb(Zr, Ti)O3 (PZT), and KNbO3. The sol-gel processing and crystallization of these films on fused silica, silicon, alumina, and single crystal SrTiO3 substrates is described.Sol-gel derived PbTiO3 thin films crystallized into the expected tetragonal perovskite structure when heated to 500 C and above. However, the crystallization of sol-gel PZT (20/80) thin films was found to be substratedependent. The heat-treated PZT films were amorphous when deposited on silica and silicon substrates. Crystalline perovskite PZT films were produced on alumina substrates, and epitaxial PZT films were produced on single-crystal SrTiO3. Heat treatment of sol-gel KNbO3 films on silicon and alumina substrates resulted in the crystallization of a variety of non-perovskite phases, but epitaxial growth of KNbO3 was observed on single crystal SrTiO3.

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Epitaxial ferroelectric thin films prepared by the Sol-Gel technique

Ferroelectrics ◽

10.1080/00150199708260538 ◽

1997 ◽

Vol 195 (1) ◽

pp. 283-288 ◽

Cited By ~ 8

Author(s):

Yuhuan Xu ◽

Chih-Hsing Cheng ◽

Yudan Lou ◽

John D. Mackenzie

Keyword(s):

Thin Films ◽

Sol Gel ◽

Ferroelectric Thin Films ◽

Gel Technique

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A Study on Optical Waveguide Application of Lanthanum III Oxide (LA O ) Thin Film Prepared 2 3 by Sol-gel Method.

NIGERIAN ANNALS OF PURE AND APPLIED SCIENCES ◽

10.46912/napas.16 ◽

2015 ◽

Vol 6 ◽

pp. 112-123

Author(s):

A A Akombor ◽

M D Tyona ◽

J SA Adelabu

Keyword(s):

Thin Film ◽

Thin Films ◽

Raman Spectroscopy ◽

Optical Waveguide ◽

Lanthanum Oxide ◽

Sol Gel ◽

Measurement Techniques ◽

Single Layer ◽

X Ray ◽

Gel Technique

Optogeometric properties of La 2 O 3 (Lanthanum Oxide) thin films prepared by sol-gel technique have been investigated. Characterization was derived by M-line spectroscopy, X-ray diffractometry and waveguide Raman Spectroscopy. M-line spectroscopy measurements revealed a refractive index of 1.592±0.001 on Pyrex substrate for a wavelength of 543.4nm and thin film thickness of 850nm and 1.589±0.001 on silicon wafer and thickness of single layer is between 40 and 60nm. X-ray diffractrometry has shown that the film has monoclinic structure. Waveguide Raman Spectroscopy has revealed a mixture of La 2 O 3 and La 2 O 2 CO 3 (Lanthanum Oxide Carbonate) which are mainly nanocrystalline and polycrystalline respectively. The research has shown that the La 2 O 3 thin films produced can be used as a planar optical waveguide. The results obtained are comparable with the works of other scientists using different measurement techniques.

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Theory of Compatible Domain Arrangements in Ferroelectric Thin Films

Volume 1: Active Materials, Mechanics and Behavior; Modeling, Simulation and Control ◽

10.1115/smasis2009-1386 ◽

2009 ◽

Cited By ~ 1

Author(s):

N. T. Tsou ◽

J. E. Huber

Keyword(s):

Thin Films ◽

Single Crystal ◽

Ferroelectric Material ◽

Ferroelectric Materials ◽

Ferroelectric Thin Films ◽

Domain Structures ◽

Crystal Films ◽

Energy Equilibrium ◽

Compatibility Theory ◽

Oriented Single Crystal

Thin films of single crystal ferroelectric material are constrained by their substrate to a fixed state of macroscopic in-plane strain. Domain structures can form to minimize the overall energy of the system by matching the imposed strain conditions in an average sense. We study low-energy equilibrium states of ferroelectric thin films using the theory of domain compatibility. In a thin film with a given state of average strain, periodic laminate microstructures can be predicted or designed using compatibility theory and the condition that domain wall orientations parallel to the substrate are prohibited by the reduction to 2-dimensions. The theory is applied to [001], [011] and [111] oriented single crystal films of tetragonal ferroelectric materials. Compatible configurations are generated and the ability of such films to be poled by electric field is then explored.

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Metal-Semiconductor-Insulator-Metal Structure Field-Effect Transistors Based on Zinc Oxides and Doped Ferroelectric Thin Films

MRS Proceedings ◽

10.1557/opl.2014.130 ◽

2014 ◽

Vol 1633 ◽

pp. 131-137 ◽

Cited By ~ 2

Author(s):

Ze Jia ◽

Jianlong Xu ◽

Xiao Wu ◽

Mingming Zhang ◽

Naiwen Zhang ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Zinc Oxide ◽

Field Effect ◽

Field Effect Transistors ◽

Sol Gel ◽

Drain Current ◽

Metal Structure ◽

Ferroelectric Materials ◽

Ferroelectric Thin Films

ABSTRACTDifferent ferroelectric thin films and their related Metal-Semiconductor-Insulator-Metal (MSIM) structures include zinc oxide (ZnO) are studied, which can be utilized in back-gated ferroelectric field-effect transistors (FETs). The most ideal zinc oxide (ZnO) thin film prepared by sol-gel method are obtained under the pyrolysis temperature of 400°C and the annealing temperature of 600°C. The asymmetric or symmetric current-voltage characteristics of the heterostructures with ZnO are exhibited depending on different ferroelectric materials in them. The curves of drain current versus gate voltage for MSIM-structure FETs are investigated, in which obvious counterclockwise loops and a drain current switching ratio up to two orders of magnitude ate observed due to the modulation effect of remnant polarization on the channel resistance. The results also indicate the positive influences of impurity atom substitution in bismuth ferrite thin film for the MSIM-structure FETs.

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