Theory of Compatible Domain Arrangements in Ferroelectric Thin Films

2009 ◽  
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.

Raman Spectroscopy of Ferroelectric Thin Films

2002 ◽  
Vol 748 ◽  
Author(s):  
R. S. Katiyar ◽  
A. Dixit ◽  
M. Jain ◽  
A. A. Savvinov ◽  
P. S. Dobal
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Structural Changes ◽  
Sol Gel ◽  
Ferroelectric Material ◽  
Ferroelectric Materials ◽  
Ferroelectric Thin Films ◽  
Structure Property ◽  
Mode Behavior ◽  
Gel Technique

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.

Ferroelectric Thin Films by sol-gel Processing

1989 ◽  
Vol 152 ◽  
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.

Domain structures of epitaxial PT, PLT and PZT thin films on MgO(001) single crystal substrates

1997 ◽  
Vol 196 (1) ◽  
pp. 5-8 ◽  
Author(s):  
Young Min Kang ◽  
Kyeong Seok Lee ◽  
Sunggi Baik
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Pzt Thin Films ◽  
Domain Structures

Epitaxial growth of Cu-Ni Single Crystal Alloys and Multilayers by Molecular Beam Epitaxy

1989 ◽  
Vol 160 ◽  
Author(s):  
R.P. Burns ◽  
Y.H. Lee ◽  
N.R. Parikh ◽  
J.B. Posthill ◽  
M.J. Mantini ◽  
...  
Keyword(s):  
Thin Films ◽  
Molecular Beam Epitaxy ◽  
Single Crystal ◽  
Epitaxial Growth ◽  
Molecular Beam ◽  
Substrate Material ◽  
High Reactivity ◽  
Lattice Match ◽  
Single Crystal Films ◽  
Crystal Films

AbstractEpitaxial growth of thin films, alloys, and multilayers from the Cu-Ni system are being explored as a means of fabricating a substrate to lattice match diamond. These single crystal films are superior to commercially available substrate material. Due to the high reactivity of the metal surfaces in atmosphere, all processing must be done under UHV conditions. In vacuo preparation, growth, and analysis of the metals is described.

Transport Studies in Single-Crystal Films of Cosi2 and Nisi2

1983 ◽  
Vol 25 ◽  
Author(s):  
J. C. Hensel ◽  
R. T. Tung ◽  
J. M. Poate ◽  
F. C. Unterwald ◽  
D. C. Jacobson
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Temperature Dependence ◽  
Room Temperature ◽  
Room Temperature Resistivity ◽  
Transport Studies ◽  
Single Crystal Films ◽  
Crystal Films ◽  
The Difference ◽  
Temperature Resistivity

ABSTRACTTransport studies have been performed on thin films of CoSi 2 and NiSis2 in the temperature range 1 to 300 K. The conductivities are metallic with essentially the same temperature dependence; however, the residual resistivities are markedly different even though the two silicides are structurally similar (the room temperature resistivity of NiSi2 being at least twice that of CoSi2 of 15 μΩ cm). The difference is attributed to intrinsic defects in NiSi2. This defect has been simulated by ion bombardment of the film where it is also shown that Matthiesen's rule is obeyed over a remarkable range of bombardment doses.

Controlled Growth of High-Temperature Superconducting Thin Films on Polycrystalline Substrates

MRS Bulletin ◽  
1992 ◽  
Vol 17 (8) ◽  
pp. 39-44 ◽  
Author(s):  
David T. Shaw
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Single Crystal ◽  
Technology Development ◽  
Magnetic Energy ◽  
High Quality ◽  
Practical Applications ◽  
High Temperature Superconducting ◽  
Controlled Processing ◽  
Crystal Films

Since their discovery in 1987, significant progress has been made in the fabrication of high-quality, high-temperature superconducting (HTS) thin films. Films with reproducible properties can be routinely deposited on single crystal substrates by several well-established processing techniques. Single crystal substrates, however, are not suitable for many applications because of their cost, limitations in size and shape, and lack of flexibility. Hence, a great deal of effort has been directed at the fabrication of thin films on polycrystalline rather than single crystal substrates. For example, metallic substrates are expected to be useful for the fabrication of HTS conductors for such applications as generators, motors, and superconducting magnetic energy storage (SMES) devices. For polycrystalline thin-film applications, lattice matching for epitaxial growth of thin films is no longer possible. Microstructures of these films are generally more complex than those of single crystal films, primarily because of grain boundaries. As a result, the microstructure of polycrystalline films must be carefully controlled to ensure that the critical current density is high enough for practical applications.Happily, progress in this respect has been substantial. There have been laboratory demonstrations of techniques for controlled processing of high-quality HTS thin films on polycrystalline substrates. Even though the technology development in this area is still in its infancy, many successful processing approaches have been developed to set the stage for the eventual use of HTS thin films in power device applications.

scholarly journals Investigation of growth characteristics and semimetal–semiconductor transition of polycrystalline bismuth thin films

IUCrJ ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 49-57 ◽  
Author(s):  
Nan Wang ◽  
Yu-Xiang Dai ◽  
Tian-Lin Wang ◽  
Hua-Zhe Yang ◽  
Yang Qi
Keyword(s):  
Thin Films ◽  
Surface Roughness ◽  
Film Thickness ◽  
Single Crystal ◽  
Growth Characteristics ◽  
Metallic Surface ◽  
Zone Model ◽  
Single Crystal Films ◽  
Crystal Films ◽  
Zone Ii

The preferred orientation growth characteristics and surface roughness of polycrystalline bismuth (Bi) thin films fabricated on glass substrates using the molecular beam epitaxy method were investigated at temperatures ranging from 18 to 150°C. The crystallization and morphology were analyzed in detail and the polycrystalline metal film structure-zone model (SZM) was modified to fit the polycrystalline Bi thin film. The boundary temperature between Zone T and Zone II in the SZM shifted to higher temperatures with the increase in film thickness or the decrease of growth rate. Furthermore, the effect of the thickness and surface roughness on the transport properties was investigated, especially for Bi thin films in Zone II. A two-transport channels model was adopted to reveal the influence of the film thickness on the competition between the metallic surface states and the semiconducting bulk states, which is consistent with the results of Bi single-crystal films. Therefore, the polycrystalline Bi thin films are expected to replace the single-crystal films in the application of spintronic devices.

Fin junction of ferroelectric thin films

2018 ◽  
Vol 11 (4) ◽  
pp. 341-371
Author(s):  
Luciano Carbone ◽  
Khaled Chacouche ◽  
Antonio Gaudiello
Keyword(s):  
Thin Films ◽  
Dimensional Reduction ◽  
Reduction Process ◽  
Ferroelectric Material ◽  
Electric Polarization ◽  
Ferroelectric Thin Films ◽  
Variational Model ◽  
Relative Thickness ◽  
Variational Models ◽  
Small Thickness

AbstractIn this paper, starting from a non-convex and nonlocal 3D-variational model for the electric polarization in a ferroelectric material, and using an asymptotic process based on dimensional reduction, we analyze junction phenomena for two orthogonal joined ferroelectric thin films. We obtain three different 2D-variational models for joined thin films, depending on how the reduction happens. Indeed, a memory effect of the reduction process appears, and it depends on the competition of the relative thickness of the two films. The guide parameter is the limit of the ratio between these two small thickness.

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