Electrochemical Organization of Gold Nanoclusters in Three Dimensions as Thin Films from an Aminosilicate-Stabilized Gold Sol and Their Characterization

Langmuir ◽  
2001 ◽  
Vol 17 (9) ◽  
pp. 2602-2609 ◽  
Author(s):  
S. Bharathi ◽  
M. Nogami ◽  
O. Lev
Keyword(s):  
Thin Films ◽  
Gold Nanoclusters ◽  
Three Dimensions ◽  
Gold Sol

Growth behavior of evaporated porous thin films

2002 ◽  
Vol 17 (11) ◽  
pp. 2904-2911 ◽  
Author(s):  
D. Vick ◽  
T. Smy ◽  
M. J. Brett
Keyword(s):  
Thin Films ◽  
Academic Motivation ◽  
Film Growth ◽  
Photonic Band Gap ◽  
Growth Dynamics ◽  
Growth Behavior ◽  
Three Dimensions ◽  
High Porosity ◽  
Physical Constraints ◽  
Deposition Parameters

Recent experimental work by a number of researchers has demonstrated that unusual high porosity thin films may be obtained in physical deposition systems by combining glancing angle deposition with in situ substrate motion control. The microstructure of these films consists of isolated columns engineered into shapes such as helices, posts, or chevrons. Due to the isolated nature of the columns, the films present a unique opportunity to study fundamental thin film growth behavior and, in particular, the influence of the self-shadowing mechanism in three dimensions. Apart from this academic motivation, there is the need to characterize the physical constraints imposed on the engineering of these films. In particular, this study will have implications for the realization of isolated, periodically arranged nanostructures envisioned for certain applications such as photonic band gap crystals. Results from an ongoing study of growth dynamics, morphology, porosity, and scaling behavior, and the dependence of these features on deposition parameters are presented.

scholarly journals Bonding Trends and Dimensionality Crossover of Gold Nanoclusters on Metal-Supported MgO Thin Films

2006 ◽  
Vol 97 (3) ◽  
Author(s):  
Davide Ricci ◽  
Angelo Bongiorno ◽  
Gianfranco Pacchioni ◽  
Uzi Landman
Keyword(s):  
Thin Films ◽  
Gold Nanoclusters

Gold nanoclusters with a wide range of fluorescence characteristics generated in situ in polymer thin films: potential gas sensing application

2017 ◽  
Vol 46 (46) ◽  
pp. 16236-16243 ◽  
Author(s):  
U. Divya Madhuri ◽  
T. P. Radhakrishnan
Keyword(s):  
Thin Films ◽  
Potential Application ◽  
Gas Sensing ◽  
Gold Nanoclusters ◽  
Emission Characteristics ◽  
Gas Detectors ◽  
Fluorescence Characteristics ◽  
Wide Range ◽  
Sensing Application

Gold nanoclusters with variable emission characteristics are generated in situ in polymer films by mild thermal annealing and their potential application as gas detectors is demonstrated.

scholarly journals Relaxation of some multi-well problems

2001 ◽  
Vol 131 (2) ◽  
pp. 279-320 ◽  
Author(s):  
Kaushik Bhattacharya ◽  
Georg Dolzmann
Keyword(s):  
Thin Films ◽  
Phase Transitions ◽  
Young Measure ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Convex Hulls ◽  
Quasiconvex Functions ◽  
Two Dimensional ◽  
Existence Of Minimizers

Mathematical models of phase transitions in solids lead to the variational problem, minimize ∫Ω W (Du) dx, where W has a multi-well structure, i.e. W = 0 on a multi-well set K and W > 0 otherwise. We study this problem in two dimensions in the case of equal determinant, i.e. for K = SO(2)U1 ∪ … ∪SO(2)Uk or K = O(2)U1 ∪ … ∪ O(2)Uk for U1, … , Uk ∈ M2×2 with det Ui = δ in three dimensions when the matrices Ui are essentially two-dimensional and also for K = SO(3)Û1 ∪ … ∪ SO(3)Ûk for U1, … , Uk ∈ M3×3 with , which arises in the study of thin films. Here, Ûi denotes the (3×2) matrix formed with the first two columns of Ui. We characterize generalized convex hulls, including the quasiconvex hull, of these sets, prove existence of minimizers and identify conditions for the uniqueness of the minimizing Young measure. Finally, we use the characterization of the quasiconvex hull to propose ‘approximate relaxed energies’, quasiconvex functions which vanish on the quasiconvex hull of K and grow quadratically away from it.

Biomimetic Mineralization of Gold Nanoclusters as Multifunctional Thin Films for Glass Nanopore Modification, Characterization, and Sensing

2017 ◽  
Vol 89 (15) ◽  
pp. 7886-7892 ◽  
Author(s):  
Sumei Cao ◽  
Shushu Ding ◽  
Yingzi Liu ◽  
Anwei Zhu ◽  
Guoyue Shi
Keyword(s):  
Thin Films ◽  
Gold Nanoclusters ◽  
Biomimetic Mineralization

Possible Causes of the Change of Dynamics in Glass-Forming Materials Subjected to Reduced Dimension

1996 ◽  
Vol 455 ◽  
Author(s):  
K. L. Ngai ◽  
A. K. Rizos
Keyword(s):  
Thin Films ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Bulk Material ◽  
Three Dimensions ◽  
Radius Of Gyration ◽  
Length Scale ◽  
Glass Forming ◽  
Reduced Dimension

ABSTRACTThere is currently many ongoing investigations of the change in the glass transition temperature when a material is reduced in dimension from the normal bulk state. The reduction in dimension can be accomplished by casting the material as thin films with or without a substrate or putting it in nanometer size pores. In this work, we explore possible causes of the change in dynamics of the bulk material when the glass-former is subjected to such modifications. The existence of a growing cooperative length scale L(T) with decreasing temperature in bulk fragile glass-forming liquids reaching the size of approximately 1.5–2.0 nm at the glass transition temperature is the basis of our consideration. When the reduced dimension is comparable to L(Tg), cooperative dynamics within a lengthscale equal to L(Tg) can no longer be maintained in all three dimensions throughout the sample. The imposed reduction of the cooperative length scale speeds up the dynamics and causes a reduction of the glass transition temperature. For polymeric glass-formers particularly at higher molecular weights, reduction of one dimension in thin films engenders orientation of the polymer chains when their radius of gyration becomes comparable to the film thickness. The latter is known to cause also a reduction of the glass transition temeperature.

STABILITY OF LARGE OPTICAL SINGLET BIPOLARONS, MANY-PARTICLE EFFECTS AND HIGH TEMPERATURE SUPERCONDUCTIVITY

1992 ◽  
Vol 06 (15) ◽  
pp. 959-966 ◽  
Author(s):  
ASHOK CHATTERJEE ◽  
SHREEKANTHA SIL
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Normal State ◽  
Entire Range ◽  
High Temperature Superconductivity ◽  
Three Dimensions ◽  
Stability Criteria ◽  
Material Parameters ◽  
Coupling Parameters ◽  
The Stability

The stability criteria for large optical bipolarons are obtained variationally for the entire range of the coupling parameters in both two and three dimensions. The size and the effective mass of these bipolarons are calculated and their variations with the material parameters are discussed. Two compounds are suggested which in the form of thin films should be tested for large bipolaronic effects. The theory is finally applied to La 2 CuO 4 and some of its normal state and superconductive properties are explained using the large bipolaronic mechanism.

Growth Behaviour of Engineered Porous Thin Films – Measurement and Modeling

2000 ◽  
Vol 648 ◽  
Author(s):  
D. Vick ◽  
T. Smy ◽  
B. Dick ◽  
S. Kennedy ◽  
M. J. Brett
Keyword(s):  
Thin Films ◽  
Academic Motivation ◽  
Film Growth ◽  
Growth Dynamics ◽  
Three Dimensions ◽  
High Porosity ◽  
Growth Behaviour ◽  
Physical Constraints ◽  
Deposition Parameters ◽  
Physical Deposition

AbstractRecent experimental work has demonstrated that unique high porosity thin films may be ob- tained in physical deposition systems by combining glancing angle deposition with in situ sub-strate motion control [1-7]. The microstructure of these films consists of isolated columns engineered into shapes such as helices, posts, or chevrons. Due to the isolated nature of the columns, the films present a unique opportunity to study fundamental thin film growth behaviour and, in particular, the influence of the self shadowing mechanism in three dimensions. Apart from this academic motivation, there is the need to characterize the physical constraints imposed on the engineering of these films. In particular, this study will have implications for the realization of isolated, periodically arranged nanostructures envisioned for certain applications. Preliminary results from an ongoing study of growth dynamics, morphology, porosity, and scaling behaviour, and the dependence of these features on deposition parameters are presented below.

LOCALIZATION IN THIN FILMS: CROSS-OVER FROM TWO DIMENSIONS TO THREE DIMENSIONS

2001 ◽  
Vol 15 (19n20) ◽  
pp. 2627-2639 ◽  
Author(s):  
R. K. BROJEN SINGH ◽  
DEEPAK KUMAR
Keyword(s):  
Thin Films ◽  
Finite Thickness ◽  
Localization Length ◽  
Finite Size ◽  
Electronic States ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Weak Disorder ◽  
Weak Scattering ◽  
Present Understanding

We have examined the localization of electronic states in disordered thin films as a function of film thickness. The study is motivated by the following consideration. According to the present understanding, in two-dimensions all electronic states are localized for any strength of disorder, however weak. Whereas in three-dimensions, there is a threshold disorder W3c, only above which all the band states are localized. We consider a film of thickness b, with a disorder strength smaller than W3c. With increasing thickness, one might expect a dimensional cross-over, so that film becomes conducting. We have examined questions that arise in this context by two techniques. The first is a finite size scaling technique due to Pichard and Sarma, in which the localization length is calculated numerically for strips and bars as a function of their lateral dimensions. Using this technique we study the delocalization of states at the band centre, as the thickness of the film is increased for moderate to strong disorders. The second technique involves the incorporation of quantum corrections to conductivity by extending the weak scattering methods to films of finite thickness. The two techniques complement each other, as the first one is more suitable for strong disorder, while the latter for weak disorder.

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