Controlling the Temperature and Speed of the Phase Transition of VO<sub>2</sub> Microcrystals

Yoon, Joonseok; Kim, Howon; Chen, Xian; Tamura, Nobumichi; Mun, Bongjin Simon; Park, Changwoo; Ju, Honglyoul

doi:10.1021/acsami.5b11144

Cited by 52 publications

(25 citation statements)

References 48 publications

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“…These observations refute the general belief that the propagation of spin domains is intrinsically slow in SCO solids (1-20 µm.s -1 ) [7,8,14,19], compared to other compounds exhibiting first-order structural phase transitions like in perovskite materials [32] or first-order metal-insulator transitions like in VO2 [33]. In these latter compounds, velocities larger than 1 mm.s -1 have been recorded.…”

Section: µMsupporting

confidence: 75%

Spatiotemporal dynamics of the spin transition in[Fe(HB(tz)3)2]single crystals

et al. 2017

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Azzedine (2017) Spatiotemporal dynamics of the spin transition in [Fe(HB(tz) ABSTRACTThe spatiotemporal dynamics of the spin transition have been thoroughly investigated in single crystals of the mononuclear spin-crossover (SCO) complex [Fe(HB(tz)3)2] (tz = 1,2,4-triazol-1-yl) by optical microscopy. This compound exhibits an abrupt spin transition centered at 334 K with a narrow thermal hysteresis loop of ca. 1 K (first-order transition). Most single crystals of this compound reveal exceptional resilience upon repeated switching (several hundred cycles), which allowed repeatable and quantitative measurements of the spatiotemporal dynamics of the nucleation and growth processes to be carried out. These experiments revealed remarkable properties of the thermally induced spin transition: high stability of the thermal hysteresis loop, unprecedented large velocities of the macroscopic lowspin/high-spin phase boundaries up to 500 µm/s and no visible dependency on the temperature scan rate. We have also studied the dynamics of the low-spin high-spin transition induced by a local photothermal excitation generated by a spatially localized (Ø = 2 µm) continuous laser beam. Interesting phenomena have been evidenced both in quasi-static and dynamic conditions (threshold effects and long incubation periods, thermal activation of the phase boundary propagation, stabilization of the crystal in a stationary biphasic state, thermal cut-off frequency). These measurements demonstrated the importance of thermal effects in the transition dynamics and allowed an accurate determination of the thermal properties of the SCO compound in the framework of a simple theoretical model. 2

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Section: µMsupporting

confidence: 75%

Spatiotemporal dynamics of the spin transition in[Fe(HB(tz)3)2]single crystals

et al. 2017

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“…An important feature of MIT in VO 2 is that, in the case of optically induced MIT, the transition occurs on a superfast time scale [12,17,21,22]. Namely, the speed of this PT reaches the order of hundreds of femtoseconds, which can become a very important factor for applications [12,17,22].…”

Section: Figmentioning

confidence: 99%

“…Namely, the speed of this PT reaches the order of hundreds of femtoseconds, which can become a very important factor for applications [12,17,22]. It should be noted that among many important tasks, temperature control and PT speed has a very high priority, since the areas and functionality of MIT applications in VO 2 strongly depend on these two parameters.…”

Section: Figmentioning

confidence: 99%

“…So in Ref. [22] the reflection of microwave electromagnetic radiation during the MIT in VO 2 is considered. It is shown that, with electromagnetic excitation on microwaves in VO 2 and its dielectric composite materials, the reflection coefficient at the MIT of the dielectric state into the metal can be tested to test both a jump-like increase and a decrease.…”

Section: Figmentioning

confidence: 99%

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The interaction of electromagnetic waves with VO2 nanosized spheres and films in optical and extremely high frequency range.

Коледов¹,

Шавров²,

Shahmirzadi³

et al. 2018

JRE

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Abstract. Recently the interaction effects of electromagnetic waves (EMW) with metallic nanoparticles and holes in nanosized films, called nano-antennas (NAs)attract great interest because of prospective applications in sensors technology. The conventional NAs and nanoparticles have fixed functionality, therefore the tunability of these structures are desired. One of the conventional method to obtain tunability is exploiting phase transition (PT) materials. Vanadium dioxide (VO 2 ) is known as a PT material and its complex dielectric constant are varied by temperature due to structural transformation, accompanying metal-insulator transition (MIT). This material is an insulator at room temperature (RT) and becomes metal above a critical temperature (T c =340 K). Hence, this material has emerged new applications in various fields. In this paper, VO 2 film on glass substrate were prepared and investigated in extremely high frequency (EHF) range (27-37 GHz). Then submicron holes arrays were formed on VO 2 films and their optical Raman spectra were studied.The special attention is paid on temperature dependence of the properties of films, holes and spheres. The study of EHF response of the nanosized VO 2 films reveals strong anomalies in the temperature range of metal-insulator transition. The RADIOELEKTRONIKI), ISSN 1684-1719, N2, 2018 2 submicron holes and arrays show strong change of the Raman spectra at the wavelength 530 nm due to heating by laser beam. Eventually, the optical properties of the homogeneous nonmagnetic VO 2 nanospheres embedded in the air are studied theoretically. The size effects on the optical properties of the VO 2 nanosphere are investigated and presented. In VO 2 nanosphere, converting into the metallic phase by heating leads to formation of a localized surface plasmon resonance (LSPR) which red shifts slightly by increasing dimension. The increment in the dimension of nanosphere in insulator case, results in the appearance of a peak in the visible wavelength most probably due to the excitation of combined electromagnetic modes. JOURNAL OF RADIO ELECTRONICS (ZHURNALThe optical spectra of VO 2 nanoparticle are much broader than that of silver nanosphere, which its associated localized electric field in form of dipolar mode is more intense than in VO 2 case. However, the LSPR of VO 2 can be thermally switched, making this material peculiar for recent advanced applications.

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“…Finally, we comment that locations with distinct variation ranges of the ambient temperature will require different designs of the passive radiative thermostat, with the appropriate phase transition setpoint constrained by the environment's yearlong thermal swings. Given the high tunability of T VO 2 PC achieved via various approaches, [41][42][43][44][45][46][47][48][49][50][51][52] it should be straightforward to design a thermostat to operate under climate conditions different from those in Los Alamos. Provided that T VO 2 PC is properly set for a given location, however, all conclusions above should hold.…”

mentioning

confidence: 99%

Passive Radiative “Thermostat” Enabled by Phase-Change Photonic Nanostructures

et al. 2018

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A thermostat senses the temperature of a physical system and switches heating or cooling devices on or off, regulating the flow of heat to maintain the system's temperature near a desired setpoint. Taking advantage of recent advances in radiative heat transfer technologies, here we propose a passive radiative "thermostat" based on phase-change photonic nanostructures for thermal regulation at room temperature. By self-adjusting their visible to mid-IR absorptivity and emissivity responses depending on the ambient temperature, the proposed devices use the sky to passively cool or heat during day-time using the phase-change transition temperature as the setpoint, while at night-time temperature is maintained at or below ambient. We simulate the 1 arXiv:1902.01354v1 [physics.optics] 4 Feb 2019 performance of a passive nanophotonic thermostat design based on vanadium dioxide thin films, showing daytime passive cooling (heating) with respect to ambient in hot (cold) days, maintaining an equilibrium temperature approximately locked within the phase transition region. Passive radiative thermostats can potentially enable novel thermal management technologies, e.g. to moderate diurnal temperature in regions with extreme annual thermal swings.

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Controlling the Temperature and Speed of the Phase Transition of VO₂ Microcrystals

Cited by 52 publications

References 48 publications

Spatiotemporal dynamics of the spin transition in[Fe(HB(tz)3)2]single crystals

Spatiotemporal dynamics of the spin transition in[Fe(HB(tz)3)2]single crystals

The interaction of electromagnetic waves with VO2 nanosized spheres and films in optical and extremely high frequency range.

Passive Radiative “Thermostat” Enabled by Phase-Change Photonic Nanostructures

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Controlling the Temperature and Speed of the Phase Transition of VO2 Microcrystals

Cited by 52 publications

References 48 publications

Spatiotemporal dynamics of the spin transition in[Fe(HB(tz)3)2]single crystals

Spatiotemporal dynamics of the spin transition in[Fe(HB(tz)3)2]single crystals

The interaction of electromagnetic waves with VO2 nanosized spheres and films in optical and extremely high frequency range.

Passive Radiative “Thermostat” Enabled by Phase-Change Photonic Nanostructures

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Controlling the Temperature and Speed of the Phase Transition of VO₂ Microcrystals