scholarly journals Controlling the near-field excitation of nano-antennas with phase-change materials

2013 ◽  
Vol 4 ◽  
pp. 632-637 ◽  
Author(s):  
Tsung Sheng Kao ◽  
Yi Guo Chen ◽  
Ming Hui Hong
Keyword(s):  
Thin Layer ◽  
Phase Change ◽  
Hot Spots ◽  
Phase Change Materials ◽  
Near Field ◽  
Plasmon Coupling ◽  
New Approach ◽  
Field Excitation ◽  
Bio Assay ◽  
Nano Antennas

By utilizing the strongly induced plasmon coupling between discrete nano-antennas and quantitatively controlling the crystalline proportions of an underlying Ge2Sb2Te5 (GST) phase-change thin layer, we show that nanoscale light localizations in the immediate proximity of plasmonic nano-antennas can be spatially positioned. Isolated energy hot-spots at a subwavelength scale can be created and adjusted across the landscape of the plasmonic system at a step resolution of λ/20. These findings introduce a new approach for nano-circuitry, bio-assay addressing and imaging applications.

scholarly journals Optical Forces on an Oscillating Dipole Near VO2 Phase Transition

Universe ◽  
2021 ◽  
Vol 7 (6) ◽  
pp. 159
Author(s):  
Daniela Szilard ◽  
Patrícia P. Abrantes ◽  
Felipe A. Pinheiro ◽  
Felipe S. S. Rosa ◽  
Carlos Farina ◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Thermal Hysteresis ◽  
Dipole Moments ◽  
Near Field ◽  
Optical Forces ◽  
Similar System ◽  
Magnetic Dipoles ◽  
Thermochromic Material ◽  
Control Light

We investigate optical forces on oscillating dipoles close to a phase change vanadium dioxide (VO2) film, which exhibits a metal-insulator transition around 340 K and low thermal hysteresis. This configuration emulates the interaction between an illuminated nanosphere and an interface and we employ a classical description to capture its important aspects. We consider both electric and magnetic dipoles for two different configurations, namely with the dipole moments parallel and perpendicular to the VO2 film. By using Bruggeman theory to describe the effective optical response of the material, we show that the thermal hysteresis present in the VO2 transition clearly shows up in the behavior of optical forces. In the near-field regime, the force on both dipoles can change from attractive to repulsive just by heating (or cooling) the film for a selected frequency range. We also verified that the optical forces are comparable to the Casimir-Polder force in a similar system, revealing the possibility of modulating or even changing the sign of the resultant force on an illuminated nano-object due to the presence of a thermochromic material. We hope that this work contributes to set the grounds for alternative approaches to control light-matter interactions using phase-change materials.

Computations with near-field coupled plasmon particles interacting with phase-change materials

2015 ◽  
Vol 121 (4) ◽  
pp. 1323-1327 ◽  
Author(s):  
Shohei Kanazawa ◽  
Kenta Kuwamura ◽  
Yuya Kihara ◽  
Yusuke Hirukawa ◽  
Toshiharu Saiki
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Near Field

scholarly journals A New Approach for Transformer Cooling Systems: Application of Phase Change Materials (PCM)

2015 ◽  
Vol 127 (4) ◽  
pp. 1013-1015 ◽  
Author(s):  
E. Buyukbicakci ◽  
I. Temiz ◽  
H. Edral ◽  
Z. Buyukbicakci
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Cooling Systems ◽  
New Approach

Nanoscale modification of phase change materials with near-field light

1996 ◽  
Vol 30 (1-4) ◽  
pp. 387-390 ◽  
Author(s):  
R. Imura ◽  
T. Shintani ◽  
K. Nakamura ◽  
S. Hosaka
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Near Field

Imaging of phase change materials below a capping layer using correlative infrared near-field microscopy and electron microscopy

2015 ◽  
Vol 107 (15) ◽  
pp. 151902 ◽  
Author(s):  
M. Lewin ◽  
B. Hauer ◽  
M. Bornhöfft ◽  
L. Jung ◽  
J. Benke ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Phase Change ◽  
Phase Change Materials ◽  
Near Field ◽  
Capping Layer

scholarly journals Degradation of Fatty Acid Phase-Change Materials (PCM): New Approach for Its Characterization

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 982
Author(s):  
Marc Majó ◽  
Ricard Sánchez ◽  
Pol Barcelona ◽  
Jordi García ◽  
Ana Inés Fernández ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Phase Change ◽  
Phase Change Materials ◽  
Capric Acid ◽  
Chemical Degradation ◽  
Thermal Treatments ◽  
New Approach ◽  
Heating And Cooling ◽  
Different Types ◽  
Thermo Physical Properties

The use of adequate thermal energy storage (TES) systems is an efficient way to achieve thermal comfort in buildings reducing the cooling and heating demand. Besides, deploy phase change materials (PCM) to meet and enhance the TES needs is highly effective and widely studied. In this paper, a study of the degradation of two fatty acids is presented, capric and myristic acids, in order to evaluate whether their thermo-physical properties are affected throughout time during service. This was carried out by means of two different types of thermal treatments: degradation at constant temperature (thermal stability test), 60 °C during 100 h and 500 h, and degradation with heating and cooling cycling (thermal cycling stability), between a temperature range from 15 °C to 70 °C with 0.5 °C/min ramp during 500 and 1000 cycles. Despite no significant changes were measured for myristic acid, experimental results revealed a decrease of melting enthalpy of 6.6% in capric acid thermally treated for 500 h. Evidences of chemical degradation were found that might explain the decrease in thermophysical properties during use.

scholarly journals Catalyst Modeling Challenges for Electrified Powertrains

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 539
Author(s):  
Thomas Souliotis ◽  
Grigorios Koltsakis ◽  
Zissis Samaras
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Management Strategies ◽  
Co2 Reduction ◽  
Exhaust System ◽  
Electrical Heating ◽  
New Approach ◽  
Vehicle Simulation ◽  
Criteria Pollutants ◽  
New Generation

To meet the upcoming CO2 reduction challenges, the further electrification of vehicle powertrains is indispensable. In combination with the post-Euro 6 requirements for criteria pollutants, the exhaust system is expected to be more complex to allow for extremely low emissions under all driving conditions, potentially involving technologies such as electrical heating and phase-change materials. The longer ‘zero-flow’ operation of the exhaust system in hybrid applications and the associated light-out risk have demanding accuracy requirements for heat loss calculations and require additional thermal management strategies. This paper discusses the additional challenges posed with regard to catalyst modeling in the boundary conditions of electrified vehicles and the necessary improvements that go beyond the state-of-the-art techniques. Most of the necessary improvements are linked to advanced 3D modeling of the exhaust system components accounting for free convection and radiative heat transfer. Modeling of electrically assisted heating is demonstrated using a new approach involving a combined 3D electrical–thermal solver. Heat retention technologies with use of phase-change materials are also accounted for in these new-generation models. Finally, the need for a tighter integration of these high-fidelity models into a vehicle simulation framework is discussed.

Crystallization fractionation technology for paraffin-based phase change materials production

2020 ◽  
pp. 33-38
Author(s):  
S.S. Kruglov (Jr.) ◽  
◽  
G.L. Patashnikov ◽  
S.S. Kruglov (Sr.) ◽  
◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Materials
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