In-Situ Tem Study of Crystallisation of Amorphous SbOx Films

1995 ◽  
Vol 404 ◽  
Author(s):  
R. Nayak ◽  
A. K. Petford-Long ◽  
R. C. Doole ◽  
C. N. Afonso
Keyword(s):  
Data Storage ◽  
Laser Pulses ◽  
Optical Data Storage ◽  
Optical Data ◽  
In Situ Tem ◽  
Video Tape ◽  
Random Nucleation ◽  
Video Frames ◽  
Potential Applications

AbstractAmorphous d.c. sputtered SbOx films (0.19< x<2.0) have been found to be fast crystallising materials sensitive to nano- and pico-second laser pulses, and have potential applications as optical data-storage media. They were crystallised in-situ in a JEOL 4000EX TEM, and the crystallisation recorded onto video tape. The crystallisation of the SbO0.37 films occurred by random nucleation followed by growth until coalescence. In contrast the crystallisation of the SbO0.533 films occurred by surface crystallisation across the whole film followed by bulk crystallisation through the film, during which contrast in the TEM increased steadily. Analysing the video frames in an image processing package enabled kinetic parameters such as transformation index and activation energy to be extracted. High resolution transmission electron microscopy showed the crystalline phase to contain nano-crystallites approximately 10 nm in size in a less-ordered matrix.

scholarly journals Photochromism in a New Light: Temperature-Dependent in situ Photocrystallography

2014 ◽  
Vol 70 (a1) ◽  
pp. C767-C767
Author(s):  
Jordan Cox ◽  
Ian Walton ◽  
Dinesh Patel ◽  
Mengyang Xu ◽  
Andrea Markelz ◽  
...  
Keyword(s):  
Data Storage ◽  
Computational Models ◽  
Incident Light ◽  
Anomalous Behavior ◽  
Optical Data Storage ◽  
Optical Data ◽  
Temperature Dependent ◽  
Photochromic Molecules ◽  
Potential Applications

Organic photochromic molecules including diarylethenes are of particular interest for their potential applications in fields of high density optical data storage and light-activated switches, among many others. However, one of the limitations in diarylethene-based systems has been the low photoconversion observed in neat single crystals which is often less than 20%. The low conversion is typically believed to be the result of screening effects in which the photoisomerized molecules at the surface absorb incident light preventing full isomerization of the crystal. To assess the effect of screening on a model diarylethene system, photocrystallographic experiments on microcrystals of the compound were performed using synchrotron radiation at the Advanced Photon Source at Argonne National Labs. During the course of the study, we discovered that the photoconversion of the diarylethene crystals exhibits highly unusual temperature dependent behavior which is incongruent with current computational models of diarylethene photochemistry. Herein we report the first temperature-dependent `constant irradiation' in situ photocrystallography experiments performed on a photochromic system. Through the application of this technique, combined with spectroscopic analysis, we demonstrate that the steady-state population arising from the photo-cyclization reaction shows a temperature dependence which has been heretofore unobserved. Possible explanations for this anomalous behavior and its role in the photochemical reactivity of this and other diarylethene systems will be presented.

Recent Progress of Electro-optic Polymers for Device Applications

1997 ◽  
Vol 488 ◽  
Author(s):  
Alex K-Y. Jen ◽  
Qing Yang ◽  
Seth R. Marder ◽  
Larry R. Dalton ◽  
Ching-Fong Shu
Keyword(s):  
Data Storage ◽  
High Speed ◽  
Stable State ◽  
Optical Data Storage ◽  
Device Fabrication ◽  
Optical Data ◽  
Material System ◽  
Electro Optic ◽  
Potential Applications ◽  
Device Applications

AbstractElectro-optic (E-O) polymers have drawn great interest in recent years because of their potential applications in photonics devices such as high speed modulators and switches, optical data storage and information processing1–2. In order to have suitable materials for device fabrication, it is essential to design and develop polymeric material systems (active and passive polymers) with matched refractive indices, large E-O coefficients, good temporal and photochemical stability3–8 The E-O response of an active polymer commonly arises from the electric field induced alignment of its second-order nonlinear optical (NLO) chromophore, either doped as a guest/host system or covalently bonded as a side-chain. Because of the strong interaction among the electric dipoles, the poled structure is in a meta-stable state; the poled NLO chromophores which possess large dipole moment will tend to relax back to the randomly oriented state. As a result, the stability of the poled structure strongly depends on the rigidity of the overall material system. As it might be expected, the continuous increases of the rigidity and Tg of poled polymers imposes constraints on the selection of suitable chromophores that can survive the hightemperature poling and processing conditions. To circumvent this problem, we have developed a series of chromophores that possess conformation-locked geometry and perfluoro-dicyanovinylsubstituted electron-accepting group which demonstrate both good thermal stabilty and nonlinearity. This paper provides a brief review of these highly efficient and thermally stable chromophores and polymers for device applications.

scholarly journals Influences of Central Units and Terminal Chains on the Banana-Shaped Liquid Crystals

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 857
Author(s):  
Tang Xin Ting ◽  
Mohd Sani Sarjadi ◽  
Md Lutfor Rahman
Keyword(s):  
Liquid Crystals ◽  
Data Storage ◽  
Smart Materials ◽  
Optical Data Storage ◽  
Optical Data ◽  
Display Devices ◽  
Functionalized Materials ◽  
Potential Applications ◽  
The Impact ◽  
Photoisomerization Process

Azo-functionalized materials are one of the appealing groups of the functionalized materials owing to their photoswitching behaviour and have been explored for various potential applications viz., optical data storage, sensor, display devices, nonlinear materials and molecular switches. Recently, azo-functionalized bent-core liquid crystals (BCLCs) have gained significant attention because they have dual properties of BCLCs and azobenzene, which enables to generate new multifaceted functional and smart materials. In this report, the recently synthesized azobenzene containing bent-core mesogens and its subclass, the so-called hockey stick and V-shaped molecules are summarized. The mesomorphic behaviour of reported BCLCs affected by the type of central core unit, the nature, number and position of the lateral substituents and the type and length of the terminal chain are discussed. The photoisomerization process of these photoresponsive BCLCs in solid, solution and mesophase, as well as the impact of light on the chemical and electrical properties of them, are discussed.

Upconversion Luminescence Behaviour of Er3+/Yb3+ Doped MY2O4 (M=Ba, Ca, Sr) Phosphors

2018 ◽  
pp. 117-148
Author(s):  
Vikas Dubey ◽  
Neha Dubey ◽  
Ravi Shrivastava ◽  
Jagjeet KaurSaluja ◽  
Sudipta Som ◽  
...  
Keyword(s):  
Rare Earth ◽  
Data Storage ◽  
Upconversion Luminescence ◽  
Optical Transmittance ◽  
Optical Data Storage ◽  
Optical Data ◽  
High Optical Transmittance ◽  
Potential Applications ◽  
Rare Earth Doped ◽  
Upconversion Process

The upconversion (UC) of the rare earth doped MY2O4 (M=Ba, Sr, Ca) has been extensively investigated due to their potential applications in many fields, such as color display, high density memories, optical data storage, sensor and energy solar cell, etc. Many series of them, especially the Er3+, Yb3+ doped MY2O4 were studied in this chapter, due to the thermal and mechanical toughness, high optical transmittance from the ultraviolet to the infrared regions, and a low nonlinear refractive index compared to the other commercial laser glasses. The energy transfer (ET) mechanism of rare earth doped phosphor plays an important role in the upconversion process.

In situ synthesis, crystallisation, and thin-film processing of single crystals of trans-[Ru(SO2)(NH3)4(H2O)][p-TolSO3]2 bearing SO2 linkage photo-isomers: towards optical device applications

CrystEngComm ◽  
2015 ◽  
Vol 17 (27) ◽  
pp. 5026-5031 ◽  
Author(s):  
J. M. Cole ◽  
K. Y. M. Yeung ◽  
G. Pace ◽  
S. O. Sylvester ◽  
D. Mersch ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Single Crystals ◽  
Data Storage ◽  
Optical Data Storage ◽  
In Situ Synthesis ◽  
Optical Data ◽  
High Quality ◽  
Device Applications

High-quality microcrystals of trans-[Ru(SO2)(NH3)4(H2O)][p-TolSO3]2 photoisomers are embedded within thin films of polyvinylacrylate, which presents opportunities for optical data storage applications.

scholarly journals Structural and optical properties of amorphous Si–Ge–Te thin films prepared by combinatorial sputtering

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
C. Mihai ◽  
F. Sava ◽  
I. D. Simandan ◽  
A. C. Galca ◽  
I. Burducea ◽  
...  
Keyword(s):  
Optical Properties ◽  
Data Storage ◽  
Optical Sensors ◽  
Material Selection ◽  
Functional Materials ◽  
Stability Study ◽  
Optical Data Storage ◽  
Optical Data ◽  
Structural And Optical Properties ◽  
Topological Constraint

AbstractThe lack of order in amorphous chalcogenides offers them novel properties but also adds increased challenges in the discovery and design of advanced functional materials. The amorphous compositions in the Si–Ge–Te system are of interest for many applications such as optical data storage, optical sensors and Ovonic threshold switches. But an extended exploration of this system is still missing. In this study, magnetron co-sputtering is used for the combinatorial synthesis of thin film libraries, outside the glass formation domain. Compositional, structural and optical properties are investigated and discussed in the framework of topological constraint theory. The materials in the library are classified as stressed-rigid amorphous networks. The bandgap is heavily influenced by the Te content while the near-IR refractive index dependence on Ge concentration shows a minimum, which could be exploited in applications. A transition from a disordered to a more ordered amorphous network at 60 at% Te, is observed. The thermal stability study shows that the formed crystalline phases are dictated by the concentration of Ge and Te. New amorphous compositions in the Si–Ge–Te system were found and their properties explored, thus enabling an informed and rapid material selection and design for applications.

scholarly journals Optical Isomerization and Photo-Patternable Properties of GeO2/Ormosils Organic-Inorganic Composite Films Doped with Azobenzene

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 818
Author(s):  
Xuehua Zhang ◽  
Qian Wang ◽  
Shun Liu ◽  
Wei Zhang ◽  
Fangren Hu ◽  
...  
Keyword(s):  
Optical Waveguide ◽  
Data Storage ◽  
Optical Switching ◽  
Sol Gel ◽  
Composite Films ◽  
Optical Data Storage ◽  
Optical Data ◽  
Single Chip ◽  
Coating Method ◽  
Inorganic Composite

GeO2/organically modified silane (ormosils) organic-inorganic composite films containing azobenzene were prepared by combining sol-gel technology and spin coating method. Optical waveguide properties including the refractive index and thickness of the composite films were characterized by using a prism coupling instrument. Surface morphology and photochemical properties of the composite films were investigated by atomic force microscope and Fourier transform infrared spectrometer. Results indicate that the composite films have smooth and neat surface, and excellent optical waveguide performance. Photo-isomerization properties of the composite films were studied by using a UV–Vis spectrophotometer. Optical switching performance of the composite films was also studied under the alternating exposure of 365 nm ultraviolet light and 410 nm visible light. Finally, strip waveguides and microlens arrays were built in the composite films through a UV soft imprint technique. Based on the above results, we believe that the prepared composite films are promising candidates for micro-nano optics and photonic applications, which would allow directly integrating the optical data storage and optical switching devices onto a single chip.

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