Optical Switching of Coherent VO2 Precipitates Embedded in Sapphire

1995 ◽  
Vol 396 ◽  
Author(s):  
L. A. Gea ◽  
L. A. Boatner ◽  
J. D. Budai ◽  
R. A. Zuhr
Keyword(s):  
Phase Transition ◽  
Vanadium Dioxide ◽  
Thermal Processing ◽  
Optical Switching ◽  
Optical Transmission ◽  
Structural Phase ◽  
Switching Behavior ◽  
New Type ◽  
Single Crystal Sapphire ◽  
Smart Surface

AbstractIn this work, we report the formation of a new type of active or “smart” surface that is produced by ion implantation and thermal processing. By co-implanting vanadium and oxygen into a single-crystal sapphire substrate and annealing the system under appropriate conditions, it was possible to form buried precipitates of vanadium dioxide that were crystallographically oriented with respect to the host AI2O3 lattice. The implanted VO2 precipitate system undergoes a structural phase transition that is accompanied by large variations in the optical transmission which are comparable to those observed for thin films of VO2 deposited on sapphire. Co-implantation with oxygen was found to be necessary to ensure good optical switching behavior.

Vanadium Dioxide Thin Films for Thermo-Optical Switching Applications

2003 ◽  
Vol 785 ◽  
Author(s):  
Lijun Jiang ◽  
William N. Carr
Keyword(s):  
Thin Films ◽  
Phase Transition ◽  
Vanadium Dioxide ◽  
Optical Switching ◽  
Abrupt Change ◽  
Metal Layer ◽  
Heating And Cooling ◽  
Optical Switching Devices ◽  
Lift Off ◽  
Vanadium Dioxide Thin Films

ABSTRACTVanadium dioxide (VO2) thin films were fabricated by e-beam evaporation of vanadium thin films followed by thermal oxidation in oxygen ambient. The properties of the VO2 films were investigated for thermo-optical switching applications. Synthesized VO2 film displays a phase transition at 65 – 68 °C. It exhibits an abrupt change in optical reflectivity over the phase transition temperature range. Results for VO2 on a highly reflective metal layer are strongly dependent on the VO2 thickness. The optical switching has a major hysteresis of about 15 °C between the heating and cooling branches. The evolution of the surface morphology with the oxidation time was studied with a SEM. The VO2 film was patterned on microplatforms by metal lift-off technique. We conclude that the evaporation followed by oxidation is an effective method to produce active VO2 film for thermo-optical switching devices.

scholarly journals Above Room Temperature Reversible Phase Transition Induces Distinct Dielectric and Nonlinear Optical Switching Response Behavior in Crown-Ether-Based Supramolecular Clathrate

Crystals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 184 ◽  
Author(s):  
Jing Jing ◽  
Fan Jiang ◽  
Yan-Li Wei ◽  
Chao Shi ◽  
Heng-Yun Ye ◽  
...  
Keyword(s):  
Phase Transition ◽  
Crown Ether ◽  
Optical Switching ◽  
Nonlinear Optical ◽  
Thermal Hysteresis ◽  
Switching Behavior ◽  
Stimuli Responsive ◽  
Scanning Calorimetry ◽  
Reversible Phase Transition ◽  
Reversible Phase

Stimuli-responsive materials with coexisting nonlinear optical (NLO) and dielectric properties are technologically important, which enable simultaneous conversion of optoelectronic properties between different states under external stimuli. By rationally screening guest cations (C6H5NF2)+ in the crown-ether inclusion system, we synthesized a crown-ether supramolecular compound [(C6H5NF2)(18-crown-6)][PF6] (1). Differential scanning calorimetry (DSC) showed that 1 undergoes a reversible phase transition above room temperatures (305 K/292 K), with a thermal hysteresis of 13 K. Temperature-dependent dielectric and NLO measurements show that the compound exhibits two distinct switching response behaviors. Structural analysis indicates that the order–disorder change of the host molecule 18-crown-6 and the guest organic cation during the phase transition induces the dielectric and NLO switching behavior of the compound.

The structural phase transition process of free-standing monoclinic vanadium dioxide micron-sized rods: temperature-dependent Raman study

RSC Advances ◽  
2015 ◽  
Vol 5 (101) ◽  
pp. 83139-83143 ◽  
Author(s):  
Huafang Zhang ◽  
Quanjun Li ◽  
Pengfei Shen ◽  
Qing Dong ◽  
Bo Liu ◽  
...  
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Vanadium Dioxide ◽  
Structural Phase ◽  
Transition Process ◽  
Temperature Dependent ◽  
Free Standing ◽  
Lower Phase ◽  
Phase Transition Process ◽  
Raman Study

Micro-sized rods show a lower phase transition temperature than nano-sized rods, and this is interpreted on the basis of nucleating defects.

Structural Phase Transition of Tungsten-Doped Vanadium Dioxide Nanopowders Prepared by Thermolysis

2008 ◽  
Vol 8 (3) ◽  
pp. 1417-1421 ◽  
Author(s):  
Zifei Peng ◽  
Wei Jiang ◽  
Heng Liu
Keyword(s):  
Phase Transition ◽  
Differential Scanning Calorimetry ◽  
Transition Temperature ◽  
Vanadium Dioxide ◽  
Structural Phase ◽  
Hysteresis Loops ◽  
Tungstic Acid ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Transmission Electron

Tungsten-doped vanadium dioxide (VO2) nanopowders were prepared by thermolysis of (NH4)5[(VO)6(CO3)4(OH)9] · 10H2O at low temperature, with active white powdery tungstic acid used as a substitutional dopant. The composition and microstructure of the powders were examined by X-ray diffraction, transmission electron microscope, and differential scanning calorimetry. The change in electrical resistance due to the S–M transition was measured from 0 to 150 °C by the four-probe method. Hysteresis loops and differential scanning calorimetry analysis of the samples indicated that the phase-transition temperature of VO2 nanopowders was 67.15 °C. For tungstendoped VO2 nanopowders, the temperature was reduced to 26.46 °C. After sintering the nanopowders, Tc rose from 26.46 °C to 34.85 °C with the sizes increasing to the bulk. A significant direct correlation between particle size and Tc was confirmed. The results indicated that white powdery tungstic acid is exceptionally effective as a dopant for reducing transition temperature.

The Structural Phase Transition in Individual Vanadium Dioxide Nanoparticles

2009 ◽  
Vol 1184 ◽  
Author(s):  
Felipe Rivera ◽  
Robert C. Davis ◽  
Richard Vanfleet
Keyword(s):  
Thin Films ◽  
Phase Transition ◽  
Vanadium Dioxide ◽  
Structural Phase ◽  
Polycrystalline Thin Films ◽  
Transmission Electron ◽  
Order Of Magnitude ◽  
Insulator Phase Transition ◽  
Means Of Transmission ◽  
Individual Particles

AbstractVanadium dioxide (VO2) single crystals undergo a structural first-order metal to insulator phase transition at approximately 68°C. This phase transition exhibits a resistivity change of up to 5 orders of magnitude in bulk specimens. We observe a 2-3 order of magnitude change in thin films of VO2. Individual particles with sizes ranging from 50 to 250 nm were studied by means of Transmission Electron Microscopy (TEM). The structural transition for individual particles was observed as a function of temperature. Furthermore, the interface between grains was also studied. We present our current progress in understanding this phase transition for polycrystalline thin films of VO2 from the view of individual particles.

Control of the Magnetic Configuration of Ferromagnetic Nanostructures Across the Structural Phase Transition of Vanadium Dioxide

2016 ◽  
Vol 7 ◽  
pp. 1-4 ◽  
Author(s):  
Simone Finizio ◽  
Mehran Vafaee ◽  
Ilya Valmiansky ◽  
Robert M. Reeve ◽  
Roberto Lo Conte ◽  
...  
Keyword(s):  
Phase Transition ◽  
Structural Phase Transition ◽  
Vanadium Dioxide ◽  
Structural Phase ◽  
Magnetic Configuration ◽  
Ferromagnetic Nanostructures

scholarly journals Parametric study of optical transmission through plasmonic hole arrays modulated by the phase transition of vanadium dioxide

OSA Continuum ◽  
2020 ◽  
Vol 3 (8) ◽  
pp. 2106
Author(s):  
Eugenii U. Donev ◽  
Francis X. Hart ◽  
Bertrand Irakoze Nkurunziza ◽  
Kevin Bertschinger ◽  
Jinlin Zhang ◽  
...  
Keyword(s):  
Phase Transition ◽  
Vanadium Dioxide ◽  
Parametric Study ◽  
Optical Transmission ◽  
Hole Arrays
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