Lattice Bending in Poly(Diacetylene) Droplets Near Surfaces

1992 ◽  
Vol 247 ◽  
Author(s):  
Patricia M. Wilson ◽  
David C. Martin
Keyword(s):  
Optical Properties ◽  
Crystal Lattice ◽  
Amorphous Carbon ◽  
Room Temperature ◽  
Droplet Surface ◽  
Molecular Organization ◽  
Direct Imaging ◽  
Chain Axis ◽  
Carbon Coated ◽  
Edge Dislocations

ABSTRACTDroplets of l, 6-di(N-carbazolyl)-2, 4 hexadiyne (DCHD) diacetylene were prepared by room temperature evaporation of dilute (0.01 wt %) solution of the monomer in chloroform on amorphous carbon-coated mica substrates. HREM and SAED examination revealed small crystallographically textured droplets (∼1 μm diameter) with cracks parallel to the [001] chain direction. The droplet geometry allowed us to investigate the structure of the polymer near edges both parallel and perpendicular to the chain axis. It was found that the curvature of the droplet edge caused a local bending of the polymer crystal lattice. The direct imaging of the molecular organization near the droplet surface allowed an investigation of the mechanisms of lattice bending via the formation of edge dislocations. An understanding of these defects is important in determining how they relate to the optical properties of poly(diacetylenes).

Dislocation mediated lattice bending in 1,6-di (N-carbazolyl)-2,4 hexadiyne (DCHD) polydiacetylene droplets

1992 ◽  
Vol 7 (11) ◽  
pp. 3150-3158 ◽  
Author(s):  
Patricia M. Wilson ◽  
David C. Martin
Keyword(s):  
Molecular Structure ◽  
Electron Microscopy ◽  
Room Temperature ◽  
High Resolution Electron Microscopy ◽  
Droplet Surface ◽  
The Core ◽  
Selected Area Electron Diffraction ◽  
Resolution Electron ◽  
Carbon Coated ◽  
Edge Dislocations

Droplets of 1,6–di (N-carbazolyl)-2,4 hexadiyne (DCHD) polydiacetylene were prepared by room temperature evaporation of dilute (0.01 wt. %) solution of the monomer in chloroform onto amorphous carbon-coated mica substrates. High Resolution Electron Microscopy (HREM) and Selected Area Electron Diffraction (SAED) revealed small crystallographically textured droplets (∼1 μm diameter) with cracks parallel to the [001] chain direction. The droplet geometry allowed us to investigate the organization of the polymer near surfaces. It was found that the curvature of the droplet edge caused a local bending of the polymer crystal lattice. Direct imaging of the molecular structure near the droplet surface revealed that the mechanism of lattice bending was by the formation of edge dislocations. Dislocations were etched in some droplets to gain information about perturbations in structure and reactivity near the core.

OPTICAL PROPERTIES OF TRIMETHYLBORON AND NITROGEN CODOPED AMORPHOUS CARBON FILMS

2002 ◽  
Vol 16 (06n07) ◽  
pp. 1096-1100 ◽  
Author(s):  
Y. HAYASHI ◽  
S. ISHIKAWA ◽  
T. SOGA ◽  
T. JIMBO ◽  
M. ADACHI ◽  
...  
Keyword(s):  
Optical Properties ◽  
Amorphous Carbon ◽  
Room Temperature ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Rf Plasma ◽  
Amorphous Carbon Films ◽  
Fabry Perot ◽  
Pl Emission ◽  
Hydrogenated Amorphous

We report on the efficient photoluminescence (PL) and optical properties of hydrogenated amorphous carbon thin films codoped with nitrogen and trimethylboron (TMB) grown by rf plasma-enhanced chemical vapor deposition at room temperature. The study clearly shows the observation of discrete PL emission peaks. The PL intensity of the film deposited with 20 sccm TMB is more than 103 times than that of the film deposited without TMB. The change of optical bandgap and PL emission energy with TMB flow rate are discussed based on sp3 and sp2 C networks. Angular dependence of the PL spectra revealed that the origin of multiple sharp peaks is due to Fabry-Perot cavity interference effect.

scholarly journals Polymorphic gallium for active resonance tuning in photonic nanostructures: from bulk gallium to two-dimensional (2D) gallenene

Nanophotonics ◽  
2020 ◽  
Vol 9 (14) ◽  
pp. 4233-4252
Author(s):  
Yael Gutiérrez ◽  
Pablo García-Fernández ◽  
Javier Junquera ◽  
April S. Brown ◽  
Fernando Moreno ◽  
...  
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Phase Change Materials ◽  
Two Dimensional ◽  
Active Materials ◽  
Promising Candidate ◽  
Plasmonic Structures ◽  
Resonance Tuning ◽  
The Many ◽  
Optical Behavior

AbstractReconfigurable plasmonics is driving an extensive quest for active materials that can support a controllable modulation of their optical properties for dynamically tunable plasmonic structures. Here, polymorphic gallium (Ga) is demonstrated to be a very promising candidate for adaptive plasmonics and reconfigurable photonics applications. The Ga sp-metal is widely known as a liquid metal at room temperature. In addition to the many other compelling attributes of nanostructured Ga, including minimal oxidation and biocompatibility, its six phases have varying degrees of metallic character, providing a wide gamut of electrical conductivity and optical behavior tunability. Here, the dielectric function of the several Ga phases is introduced and correlated with their respective electronic structures. The key conditions for optimal optical modulation and switching for each Ga phase are evaluated. Additionally, we provide a comparison of Ga with other more common phase-change materials, showing better performance of Ga at optical frequencies. Furthermore, we first report, to the best of our knowledge, the optical properties of liquid Ga in the terahertz (THz) range showing its broad plasmonic tunability from ultraviolet to visible-infrared and down to the THz regime. Finally, we provide both computational and experimental evidence of extension of Ga polymorphism to bidimensional two-dimensional (2D) gallenene, paving the way to new bidimensional reconfigurable plasmonic platforms.

Role of non-magnetic dopants on the room temperature ferromagnetism and optical properties of BaSnO3 perovskite

2020 ◽  
Vol 281 ◽  
pp. 121028 ◽  
Author(s):  
Saad Mabrouk Yakout ◽  
Hanan A. Mousa ◽  
Hala T. Handal ◽  
Walid Sharmoukh
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism

Electrical and Optical Properties of Si+ and P+ Implanted InP:Fe

1990 ◽  
Vol 201 ◽  
Author(s):  
Honglie Shen ◽  
Genqing Yang ◽  
Zuyao Zhou ◽  
Guanqun Xia ◽  
Shichang Zou
Keyword(s):  
Optical Properties ◽  
Silicon Nitride ◽  
Temperature Dependence ◽  
Optimal Condition ◽  
Room Temperature ◽  
Broad Band ◽  
Photoluminescence Spectra ◽  
Electrical And Optical Properties ◽  
Spectrum Measurement ◽  
Single Implant

AbstractDual implantations of Si+ and P+ into InP:Fe were performed both at 200°C and room temperature. Si+ ions were implanted by 150keV with doses ranging from 5×1013 /cm2 to 1×1015 /cm2, while P+ ions were implanted by 110keV. 160keV and 180keV with doses ranging from 1×l013 /cm2 to 1×1015 /cm2. Hall measurements and photoluminescence spectra were used to characterize the silicon nitride encapsulated annealed samples. It was found that enhanced activation can be obtained by Si+ and P+ dual implantations. The optimal condition for dual implantations is that the atomic distribution of implanted P overlaps that of implanted si with the same implant dose. For a dose of 5×l014 /cm2, the highest activation for dual implants is 70% while the activation for single implant is 40% after annealing at 750°C for 15 minutes. PL spectrum measurement was carried out at temperatures from 11K to 100K. A broad band at about 1.26eV was found in Si+ implanted samples, of which the intensity increased with increasing of the Si dose and decreased with increasing of the co-implant P+ dose. The temperature dependence of the broad band showed that it is a complex (Vp-Sip) related band. All these results indicate that silicon is an amphoteric species in InP.

One-pot synthesis of carbon coated Fe3O4 nanosheets with superior lithium storage capability

2015 ◽  
Vol 3 (8) ◽  
pp. 4716-4721 ◽  
Author(s):  
Guoxin Gao ◽  
Shiyao Lu ◽  
Bitao Dong ◽  
Zhicheng Zhang ◽  
Yuansuo Zheng ◽  
...  
Keyword(s):  
Amorphous Carbon ◽  
Large Scale ◽  
Solution Method ◽  
Lithium Storage ◽  
One Pot ◽  
One Pot Synthesis ◽  
Carbon Coated ◽  
Storage Properties

Large-scale flat Fe3O4 nanosheets coated by an amorphous carbon overlayer (denoted as Fe3O4@C NSs) was prepared via a simple one-pot solution method. When evaluated as an electrode for LIBs, the as-prepared Fe3O4@C NSs hybrids exhibit highly enhanced lithium storage properties.

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