TEM Observation of Natural Rubber Thin Films Crystallized under Molecular Orientation

2000 ◽  
Vol 73 (5) ◽  
pp. 926-936 ◽  
Author(s):  
Toshiki Shimizu ◽  
Masatoshi Tosaka ◽  
Masaki Tsuji ◽  
Shinzo Kohjiya
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Natural Rubber ◽  
Isothermal Crystallization ◽  
Molecular Orientation ◽  
Benzene Solution ◽  
Dark Field ◽  
In Situ Tem ◽  
Time Resolved ◽  
Specimen Holder

Abstract Morphology of natural rubber (NR) thin films crystallized under molecular orientation was examined by transmission electron microscopy (TEM). A thin film of NR (RSS#1) was made by casting its n-hexane (or benzene) solution onto the water surface, and prestretched up to a desired amount of strain (%). Each of the specimens thus prepared was introduced into a TEM column and isothermally crystallized at −25 °C with a cryo-transfer specimen-holder. Morphological observations in bright- and dark-field imaging modes revealed directly that the length of the lamellae, which were oriented perpendicular to the stretching direction, decreased with increasing strain. The result seems to be related to the population density of “γ-filaments” (named by Andrews) generated only by prestretching. Time-resolved bright-field observations by in situ TEM of the thin film prestretched up to a strain of 200% revealed the following. Though the film gave crystalline reflections in its selected-area electron diffraction even before isothermal crystallization, no well-defined lamellae were recognized. Subsequent isothermal crystallization for 2 h, however, formed well-defined lamellae oriented perpendicular to the stretching direction. This observation, conceivably, suggests that “γ-filaments” were formed immediately by prestretching and then the lamellae were nucleated on the γ-filaments at −25 °C.

Crystallization kinetics of amorphous Ga–Sb–Te films: Part II. Isothermal studies by a time-resolved optical transmission method

2004 ◽  
Vol 19 (10) ◽  
pp. 2938-2946 ◽  
Author(s):  
Chain-Ming Lee ◽  
Yeong-Iuan Lin ◽  
Tsung-Shune Chin
Keyword(s):  
Thin Films ◽  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Optical Transmission ◽  
Isothermal Kinetics ◽  
Initial Surface ◽  
Transmission Method ◽  
Time Resolved ◽  
Stage 1 ◽  
Kinetics Of

Isothermal crystallization kinetics of amorphous Ga–Sb–Te films was studied by means of a time-resolved optical transmission method. Thin films with compositions along the pseudo-binary tie-lines Sb7Te3–GaSb and Sb2Te3–GaSb in the ternary phase diagram were prepared by the co-sputtering method. Crystallization of GaSbTe films reveals a two-stage process: an initial surface nucleation and coarsening (Stage 1) followed by the one-dimensional grain growth (Stage 2). The kinetic exponent (n) value in Stage 1 shows strong dependence on film compositions, while that of Stage 2 is less dependent. The activation energy in Stage 1 increases with increasing GaSb content and reaches the maximum values at compositions close to GaSb, but a decreasing trend was observed in Stage 2. Kinetics parameters between isothermal crystallization of thin films and non-isothermal crystallization of powder samples analyzed by differential scanning colorimetry [J. Mater. Res. 19, 2929 (2004)] are compared. The kinetic parameters in Stage 1 show much correspondence with those of non-isothermal cases in comparable kinetic exponents but with lower activation energies. The discrepancies between nonisothermal and isothermal kinetics are attributed to the sample morphology and the constraint effects.

In-Situ Tem Characterization of Whiskers on Al Electrodes for Thin-Film Transistors

1996 ◽  
Vol 441 ◽  
Author(s):  
K. Tsujimoto ◽  
S. Tsuji ◽  
H. Saka ◽  
K. Kuroda ◽  
H. Takatsuji ◽  
...  
Keyword(s):  
Thin Film ◽  
High Voltage ◽  
Focused Ion Beam ◽  
Liquid Crystal Display ◽  
Ion Beam ◽  
Thin Film Transistor ◽  
Dark Field ◽  
Growth Stages ◽  
In Situ Tem

AbstractThe recent attention paid to stress migration of aluminum (Al) electrodes in thin-film transistor liquid crystal display (TFT-LCD) applications indicates that wiring materials with low electrical resistivities are of considerable interest for their potential use in higher-resolution displays. In this paper, we firstly describe how as-grown Al whiskers on Al electrodes fabricated on a LCD-grade glass substrate can be characterized by means of a high-voltage transmission electron microscope (HV-TEM) operated at 1 MV. The whiskers ranging from 300 to 400 nm in diameter are sufficient to be transparent to high-voltage electrons. This allows detailed observation of whisker characteristics such as its morphology and crystallography. In most cases, the as-grown Al whiskers in our study had straight rod shapes, and could be regarded as single crystals. Secondly, we report on the in-situ fabrication and observation of Al whiskers at elevated temperature with the HV-TEM. Since relatively thick TEM samples (up to about 1 mm) can be set on a sample holder in the HV-TEM, various growth stages of Al whiskers can be investigated under various heating conditions. Finally, we demonstrate a TEM sample preparation method for the cross-section of an individual Al whisker, using focused ion beam (FIB) etching. This technique makes it possible to reduce the thickness of an Al whisker close to the root. Both bright- and dark-field TEM images provide nanostructural information on the whisker/Al thin-film interface.

scholarly journals Narrowband Spontaneous Emission Amplification from a Conjugated Oligomer Thin Film

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 232
Author(s):  
Mohamad S. AlSalhi ◽  
Mamduh J. Aljaafreh ◽  
Saradh Prasad
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Properties ◽  
Absorption Spectrum ◽  
Spontaneous Emission ◽  
Spin Coating ◽  
Quartz Substrate ◽  
Pump Energy ◽  
Laser Induced Fluorescence ◽  
Time Resolved

In this paper, we studied the laser and optical properties of conjugated oligomer (CO) 1,4-bis(9-ethyl-3-carbazo-vinylene)-9,9-dihexyl-fluorene (BECV-DHF) thin films, which were cast onto a quartz substrate using a spin coating technique. BECV-DHF was dissolved in chloroform at different concentrations to produce thin films with various thicknesses. The obtained results from the absorption spectrum revealed one sharp peak at 403 nm and two broads at 375 and 428 nm. The photoluminescence (PL) spectra were recorded for different thin films made from different concentrations of the oligomer solution. The threshold, laser-induced fluorescence (LIF), and amplified spontaneous emission (ASE) properties of the CO BECV-DHF thin films were studied in detail. The ASE spectrum was achieved at approximately 482.5 nm at a suitable concentration and sufficient pump energy. The time-resolved spectroscopy of the BECV-DHF films was demonstrated at different pump energies.

scholarly journals Rapid Solidification in Thin-Film Al-Cu Alloys: Capturing the Dynamics with Time-Resolved In Situ TEM

2014 ◽  
Vol 20 (S3) ◽  
pp. 1580-1581
Author(s):  
Joseph T. McKeown ◽  
Kai Zweiacker ◽  
Thomas LaGrange ◽  
Bryan W. Reed ◽  
Can Liu ◽  
...  
Keyword(s):  
Thin Film ◽  
Rapid Solidification ◽  
In Situ Tem ◽  
Time Resolved ◽  
Cu Alloys

scholarly journals TEM Studies on Thin Films of Natural Rubber and Polychloroprene Crystallized under Molecular Orientation

1999 ◽  
Vol 31 (9) ◽  
pp. 784-789 ◽  
Author(s):  
Masaki Tsuji ◽  
Toshiki Shimizu ◽  
Shinzo Kohjiya
Keyword(s):  
Thin Films ◽  
Natural Rubber ◽  
Molecular Orientation

Molecular orientation in single crystal thin films of N-(4-nitrophenyl)-(L)-prolinol

1998 ◽  
Vol 13 (1) ◽  
pp. 131-134 ◽  
Author(s):  
Ligui Zhou ◽  
M. Thakur
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Single Crystal ◽  
Molecular Orientation ◽  
Second Harmonic ◽  
Substrate Surface ◽  
X Ray Diffraction ◽  
X Ray ◽  
Single Crystal Films ◽  
Crystal Films

Thin single crystal films of N-(4-nitrophenyl)-(L)-prolinol (NPP) were prepared using the modified shear method. The surface orientation of the single crystal films was determined by x-ray diffraction and was found to be [101]. Polarized microscopy showed uniform birefringence and complete extinction when the thin film was rotated under crossed polarization, implying single crystal thin films with uniform surface were obtained. The molecular orientation in the NPP thin film was studied by polarized UV-visible and polarized micro-FTIR spectroscopy along with x-ray diffraction. The orientation of the NPP molecules was found to be almost parallel to the plane of the film. This parallel orientation is because of the polar (hydrogen bonding) interaction of the −(OH) and the N=O groups of the NPP molecule with the hydrophilic substrate surface. The results of the second harmonic generation (SHG) measurements are consistent with such a molecular orientation. These results show that the final molecular and crystallographic orientation in the film is determined by its initial molecule-substrate interaction.

In Situ Spectroscopy and Modeling of Deformation Behavior of Nanoscale Interfacial Materials

2011 ◽  
Vol 1297 ◽  
Author(s):  
Takakazu Suzuki ◽  
W. Suetaka ◽  
A. Suzuki ◽  
T. Sato ◽  
T. Suzuki
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Deformation Behavior ◽  
Molecular Orientation ◽  
In Situ Spectroscopy ◽  
Dynamics Simulations ◽  
Interfacial Films

ABSTRACTIn this work, the behavior of molecules in thin-film lubricants, several tens of nanometers thick, is studied by in situ reflection infrared spectroscopy and by molecular dynamics simulations. The effect of fatty acid additives on the properties of these interfacial films is also studied. The results of these experiments are presented and interpreted, and the latest outcomes of molecular dynamics simulations are discussed. It is concluded that the molecular orientation in thin films of interfacial materials is markedly affected by the use of additives.

The Aspects of Thermal Anneal to Intrinsic Stress and Hicrostructure of Multilayer Thin Films

1989 ◽  
Vol 153 ◽  
Author(s):  
C. H. Yang ◽  
P.C. Chen
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Adhesion Strength ◽  
Molecular Orientation ◽  
Annealing Temperature ◽  
Stress Measurement ◽  
Degradation Mechanism ◽  
Intrinsic Stress ◽  
Multilayer Thin Films ◽  
Steady Decrease

AbstractAdhesion degradation mechanism at the interface of a multilayer thin film was studied as a function of annealing temperature. The multilayer thin films employed for current investigation of the temperature effect were constructed by sputtering 500 Å Cr and 10K Å Cu on both sides of kapton. A steady decrease of adhesion strength was found as a result of increasing the annealing temperature from 150°C to 350°C. Thin film and interfacial properties in association with degradation of adhesion were characterized by several techniques, including intrinsic stress measurement, Auger, TEN and SIMS. Several changes were observed by elevating the annealing temperature. It was found that the intrinsic stress in each layer changed. Both Cu and Cr grain size increased with the annealing temperature. The interface at kapton and metal became more defined. The Cu atoms were found to become mobile and diffused into Cr and kapton layer after a 350 degree annealing. In addition, a change of molecular orientation and chemistry in kapton near the interface was observed by SIMS and XPS studies. A combination of these factors resulted in a decline of adhesion strength.

Enhanced 1.5 μm luminescence lifetime of vacuum deposited erbium-doped organic thin films for optical amplification applications

2012 ◽  
Vol 1471 ◽  
Author(s):  
Christophe Galindo ◽  
Laurent Divay ◽  
Françoise Soyer ◽  
Evelyne Chastaing ◽  
Renato Bisaro ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Cross Sections ◽  
Luminescence Lifetime ◽  
Organic Polymer ◽  
Vacuum Sublimation ◽  
Time Resolved ◽  
Optical Amplification ◽  
Erbium Doped ◽  
Doped Glasses

ABSTRACTInorganic erbium-doped glasses are widely used in telecommunications due to the sharp intra-atomic 4I13/2 → 4I15/2 transition in the 4f orbital of erbium resulting in an emission at ∼ 1.5 μm, which is the low loss window of silica optical fibres. The limited erbium concentration of about 1020 ions/cm3 in inorganic erbium-doped glasses and the low absorption coefficient of the Er3+ ions, imply that relatively long lengths of fibre are required. Organic erbium complexes present higher absorption cross sections due to the photosensitization of erbium by the organic conjugated ligands and broader emission bands than those of the free Er3+ ions. Such properties open the possibility to develop compact, low power and broadband infrared emitting devices. We present the study of an organic fluorinated erbium complex exhibiting 1.5 μm luminescence lifetime of several hundreds of microseconds measured on thin film. The organic complex has been deposited by vacuum sublimation technique. This deposition method allows the realization of an erbium-doped thin film without the help of an organic polymer matrix, which is a potential source of vibrationnal luminescence quenching. We report the synthesis, the sublimation process, and the characterization of the thin films. The chemical structure of the complex is assessed by FTIR, NMR and MALDI-TOF. Chemical integrity of the thin film after vacuum deposition is determined by FTIR. The morphology of the thin film is characterized by X-ray diffraction experiments. The optical properties of the thin film are determined by spectroscopic ellipsometry, UV-Vis-NIR absorption spectroscopy and time resolved NIR photoluminescence spectroscopy.

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