Microstructure Evolution of Epitaxial (Ba, Sr) TiO3/ (001) HgO Thin Films

ABSTRACTSurface and cross-section relief evolution of ferroelectric epitaxial (Ba,Sr)TiO3 films rf-sputtered on (001) HgO crystal cle-avage surface versus the oxygen worKing gas pressure P and subst-rate temperature T were studied. Specific features of both three-dimensional and two-dimensional epitaxy mechanisms corresponding to various deposition conditions were revealed. Difference between low and high P-T-value 3D epitaxy was established. The deposition of films with mirror-smooth surfaces and perfect interfaces is shown to be possible.

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Surface and Interface Microstructure of Epitaxial Ferroelectric (Ba, Sr)Tio3 Thin Films

MRS Proceedings ◽

10.1557/proc-388-411 ◽

1995 ◽

Vol 388 ◽

Author(s):

V. A. Alyoshin ◽

E. V. Sviridov ◽

Vi. M. Mukhortov ◽

I. N. Zakharchenko ◽

V. P. Dudkevich

Keyword(s):

Thin Films ◽

Substrate Temperature ◽

Cross Section ◽

Three Dimensional ◽

Gas Pressure ◽

Smooth Surfaces ◽

Interface Microstructure ◽

Two Dimensional ◽

Surface And Interface ◽

Deposition Conditions

AbstractSurface and cross-section relief evolution of ferroelectric epitaxial (Ba,Sr)Ti03 films rf-sputtered on (001) MgO crystal cleavage surfaces versus the oxygen worKing gas pressure P and substrate temperature T were studied. Specific features of both three-dimensional and two-dimensional epitaxy mechanisms corresponding to various deposition conditions were revealed. Difference between low and high P-T-value 3D epitaxy was established. the deposition of films with mirror-smooth surfaces and perfect interfaces is shown to be possible.

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Nanometer-Thick [(FPEA)2PbX4; X=I, Br] 2D Halide Perovskite Based Thin Films for Pollutant Detection and Nonconventional Photocatalytic Degradation

Materials Advances ◽

10.1039/d1ma00561h ◽

2021 ◽

Author(s):

Arindam Mondal ◽

Akash Lata ◽

Aarya Prabhakaran ◽

Satyajit Gupta

Keyword(s):

Thin Films ◽

Photocatalytic Degradation ◽

Three Dimensional ◽

Two Dimensional ◽

Reduced Dimensionality ◽

P Application ◽

Halide Perovskites ◽

Halide Perovskite ◽

Pollutant Detection

Application of three-dimensional (3D)-halide perovskites (HaP) in photocatalysis encourages the new exercise with two-dimensional (2D) HaP based thin-films for photocatalytic degradation of dye. The reduced dimensionality to 2D-HaPs, with a...

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Plane turbulent jets in a bounded fluid layer

Journal of Fluid Mechanics ◽

10.1017/s0022112092002167 ◽

1992 ◽

Vol 241 ◽

pp. 587-614 ◽

Cited By ~ 76

Author(s):

T. Dracos ◽

M. Giger ◽

G. H. Jirka

Keyword(s):

Experimental Investigation ◽

Cross Section ◽

Fluid Layer ◽

Three Dimensional ◽

Turbulent Jets ◽

Two Dimensional ◽

Vortical Structures ◽

Secondary Currents ◽

Fluid Layers ◽

Bounding Surfaces

An experimental investigation of plane turbulent jets in bounded fluid layers is presented. The development of the jet is regular up to a distance from the orifice of approximately twice the depth of the fluid layer. From there on to a distance of about ten times the depth, the flow is dominated by secondary currents. The velocity distribution over a cross-section of the jet becomes three-dimensional and the jet undergoes a constriction in the midplane and a widening near the bounding surfaces. Beyond a distance of approximately ten times the depth of the bounded fluid layer the secondary currents disappear and the jet starts to meander around its centreplane. Large vortical structures develop with axes perpendicular to the bounding surfaces of the fluid layer. With increasing distance the size of these structures increases by pairing. These features of the jet are associated with the development of quasi two-dimensional turbulence. It is shown that the secondary currents and the meandering do not significantly affect the spreading of the jet. The quasi-two-dimensional turbulence, however, developing in the meandering jet, significantly influences the mixing of entrained fluid.

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Derivation of Equations for a Size Distribution of Spherical Particles in Non-Transparent Materials

Journal of Casting & Materials Engineering ◽

10.7494/jcme.2021.5.4.53 ◽

2021 ◽

Vol 5 (4) ◽

pp. 53-60

Author(s):

Daniel Gurgul ◽

Andriy Burbelko ◽

Tomasz Wiktor

Keyword(s):

Probability Density Function ◽

Probability Density ◽

Size Distribution ◽

Density Function ◽

Cross Section ◽

Three Dimensional ◽

Spherical Particles ◽

Two Dimensional ◽

Mathematical Formulas ◽

Transparent Materials

This paper presents a new proposition on how to derive mathematical formulas that describe an unknown Probability Density Function (PDF3) of the spherical radii (r3) of particles randomly placed in non-transparent materials. We have presented two attempts here, both of which are based on data collected from a random planar cross-section passed through space containing three-dimensional nodules. The first attempt uses a Probability Density Function (PDF2) the form of which is experimentally obtained on the basis of a set containing two-dimensional radii (r2). These radii are produced by an intersection of the space by a random plane. In turn, the second solution also uses an experimentally obtained Probability Density Function (PDF1). But the form of PDF1 has been created on the basis of a set containing chord lengths collected from a cross-section.The most important finding presented in this paper is the conclusion that if the PDF1 has proportional scopes, the PDF3 must have a constant value in these scopes. This fact allows stating that there are no nodules in the sample space that have particular radii belonging to the proportional ranges the PDF1.

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Tip-Based Nanomachining on Thin Films: A Mini Review

Nanomanufacturing and Metrology ◽

10.1007/s41871-021-00115-5 ◽

2021 ◽

Author(s):

Shunyu Chang ◽

Yanquan Geng ◽

Yongda Yan

Keyword(s):

Thin Film ◽

Thin Films ◽

Data Storage ◽

Three Dimensional ◽

Maintenance Cost ◽

Two Dimensional ◽

Force Microscopy ◽

Atomic Force ◽

Current State ◽

Two Dimensional Materials

AbstractAs one of the most widely used nanofabrication methods, the atomic force microscopy (AFM) tip-based nanomachining technique offers important advantages, including nanoscale manipulation accuracy, low maintenance cost, and flexible experimental operation. This technique has been applied to one-, two-, and even three-dimensional nanomachining patterns on thin films made of polymers, metals, and two-dimensional materials. These structures are widely used in the fields of nanooptics, nanoelectronics, data storage, super lubrication, and so forth. Moreover, they are believed to have a wide application in other fields, and their possible industrialization may be realized in the future. In this work, the current state of the research into the use of the AFM tip-based nanomachining method in thin-film machining is presented. First, the state of the structures machined on thin films is reviewed according to the type of thin-film materials (i.e., polymers, metals, and two-dimensional materials). Second, the related applications of tip-based nanomachining to film machining are presented. Finally, the current situation of this area and its potential development direction are discussed. This review is expected to enrich the understanding of the research status of the use of the tip-based nanomachining method in thin-film machining and ultimately broaden its application.

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Membrane analogy for multi-material bars under torsion

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2019.0124 ◽

2019 ◽

Vol 475 (2225) ◽

pp. 20190124 ◽

Cited By ~ 2

Author(s):

Laura Galuppi ◽

Gianni Royer-Carfagni

Keyword(s):

Finite Element ◽

Cross Section ◽

Cross Sections ◽

Three Dimensional ◽

Element Model ◽

Elastic Problem ◽

Two Dimensional ◽

Torsion Problem ◽

Linear Elastic ◽

Physical Apparatus

Prandtl's membrane analogy for the torsion problem of prismatic homogeneous bars is extended to multi-material cross sections. The linear elastic problem is governed by the same equations describing the deformation of an inflated membrane, differently tensioned in regions that correspond to the domains hosting different materials in the bar cross section, in a way proportional to the inverse of the material shear modulus. Multi-connected cross sections correspond to materials with vanishing stiffness inside the holes, implying infinite tension in the corresponding portions of the membrane. To define the interface constrains that allow to apply such a state of prestress to the membrane, a physical apparatus is proposed, which can be numerically modelled with a two-dimensional mesh implementable in commercial finite-element model codes. This approach presents noteworthy advantages with respect to the three-dimensional modelling of the twisted bar.

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Computational Study of Zigzag Spacer Design with Elliptical Cross-Section Filaments

MATEC Web of Conferences ◽

10.1051/matecconf/202030701047 ◽

2020 ◽

Vol 307 ◽

pp. 01047

Author(s):

Gohar Shoukat ◽

Farhan Ellahi ◽

Muhammad Sajid ◽

Emad Uddin

Keyword(s):

Mass Transfer ◽

Cross Section ◽

Cross Sections ◽

Computational Study ◽

Flow Direction ◽

Three Dimensional ◽

Circular Cross Section ◽

Two Dimensional ◽

Permeate Flux ◽

Elliptical Cross

The large energy consumption of membrane desalination process has encouraged researchers to explore different spacer designs using Computational Fluid Dynamics (CFD) for maximizing permeate per unit of energy consumed. In previous studies of zigzag spacer designs, the filaments are modeled as circular cross sections in a two-dimensional geometry under the assumption that the flow is oriented normal to the filaments. In this work, we consider the 45° orientation of the flow towards the three-dimensional zigzag spacer unit, which projects the circular cross section of the filament as elliptical in a simplified two-dimensional domain. OpenFOAM was used to simulate the mass transfer enhancement in a reverse-osmosis desalination unit employing spiral wound membranes lined with zigzag spacer filaments. Properties that impact the concentration polarization and hence permeate flux were analyzed in the domain with elliptical filaments as well as a domain with circular filaments to draw suitable comparisons. The range of variation in characteristic parameters across the domain between the two different configurations is determined. It was concluded that ignoring the elliptical projection of circular filaments to the flow direction, can introduce significant margin of error in the estimation of mass transfer coefficient.

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