Terahertz time domain spectroscopy of amorphous and crystalline aluminum oxide nanostructures synthesized by thermal decomposition of AACH

Mehboob, Shoaib; Mehmood, Mazhar; Ahmed, Mushtaq; Ahmad, Jamal; Tanvir, Muhammad Tauseef; Ahmad, Izhar; Hassan, Syed Mujtaba ul

doi:10.1016/j.matchemphys.2017.01.030

Cited by 13 publications

(6 citation statements)

References 49 publications

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“…Further, heavier atoms (i.e., Cd) have higher electronic polarizability, which supports the higher dielectric constant of Cd-MOF. Similar behavior of the real dielectric constant is also observed for crystalline and amorphous aluminum oxide …”

Section: Resultssupporting

confidence: 78%

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Pt-Ni@PC900 Hybrid Derived from Layered-Structure Cd-MOF for Fuel Cell ORR Activity

et al. 2020

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Fuel cell technology is the supreme alternate option for the replacement of fossil fuel in the current era. Pt alloys can perform well as fuel cell electrodes for being used as catalytic materials to perform the very notorious oxygen reduction reaction. In this regard, first, a layered metal− organic framework with empirical formula [C 8 H 10 CdO 7 ] n • 4H 2 O is synthesized and characterized using various experimental and theoretical techniques. Then, a nanostructured porous carbon material with a sheet morphology (PC900) having a high BET surface area of 877 m 2 g −1 is fabricated by an inert-atmosphere thermal treatment of the framework upon heating up to 900 °C. Pt and Ni nanoparticles are embedded into PC900 to prepare a homogenized hybrid functional material, i.e.,

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Section: Resultssupporting

confidence: 78%

“…Similar behavior of the real dielectric constant is also observed for crystalline and amorphous aluminum oxide. 51 2.5. NLO Properties.…”

Section: Resultsmentioning

confidence: 99%

Pt-Ni@PC900 Hybrid Derived from Layered-Structure Cd-MOF for Fuel Cell ORR Activity

et al. 2020

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“…EMMs provide a way to do so. The most basic EMM considers a linear dependence [rule of mixtures or Vegard's law (V) [8], [9]] giving the effective permittivity of the pellet, 𝜀 𝑒𝑓𝑓 = 𝑓 𝑉 𝜀 𝑖 + (1 − 𝑓 𝑉 )𝜀 ℎ , where εi and εh are the inclusion and host permittivity respectively; the host volume fill factor is 1-fV.…”

Section: Introductionmentioning

confidence: 99%

Terahertz Permittivity of Pressed ZnO and CuO Powder in Polyethylene Pellets: Effect of Porosity

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Bouscaud

et al. 2021

IEEE Trans. THz Sci. Technol.

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Terahertz (THz) spectroscopy is used to measure permittivity (100 GHz-2.5 THz) of ZnO and CuO powders with low fill factor pressed into pellets in a polyethylene binder. We show that porosity (air) of such pressed pellets has a large effect on effective pellet permittivity (~10 %) and on the extracted permittivity of the oxide constituent (~150 %). We explore a twostep analysis based on sequential application of different effective medium models (EMMs), first to account for the air, and subsequently to extract the oxide's dielectric properties. We show that the combination of the Vegard's law and the Maxwell Garnett is the best to account, respectively, for the air and the oxides. In this regard, the capacity that this approach has to adapt to each phase's physical characteristics by using multiple EMMs is an advantage. The resulting oxide permittivities are significantly larger than previously reported for such pellets as a consequence of the porosity. We find for the real relative permittivities of CuO and ZnO ~12.1 and ~8.9, respectively, in the THz range.

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“…As for structure sizes, they all refer to the actual ones of the modulator, as shown in Figure 1c. The specific parameters not mentioned before are set as follows: the dielectric constant of PET ε PET = 3, the conductivity of the aluminum layer δ Al = 3.56 × 10 7 S/m, the dielectric constant of the aluminum oxide layer ε Alumina = 6 [41], and the dielectric constant of the solid electrolyte layer ε Solid−electrolyte = 5.5 [37]. The conductivity of graphene, σ graphene , is defined by the formula [42]:…”

Section: Discussionmentioning

confidence: 99%

Low Voltage Graphene-Based Amplitude Modulator for High Efficiency Terahertz Modulation

et al. 2020

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In this paper, a high-efficiency terahertz amplitude modulation device based on a field-effect transistor has been proposed. The polarization insensitive modulator is designed to achieve a maximum experimental modulation depth of about 53% within 5 V of gate voltages using monolayer graphene. Moreover, the manufacturing processes are inexpensive. Two methods are adopted to improve modulation performance. For one thing, the metal metamaterial designed can effectively enhance the electromagnetic field near single-layer graphene and therefore greatly promote the graphene’s modulation ability in terahertz. For another, polyethylene oxide-based electrolytes (PEO:LiClO4) acts as a high-capacity donor, which makes it possible to dope single-layer graphene at a relatively low voltage.

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Terahertz time domain spectroscopy of amorphous and crystalline aluminum oxide nanostructures synthesized by thermal decomposition of AACH

Cited by 13 publications

References 49 publications

Pt-Ni@PC900 Hybrid Derived from Layered-Structure Cd-MOF for Fuel Cell ORR Activity

Pt-Ni@PC900 Hybrid Derived from Layered-Structure Cd-MOF for Fuel Cell ORR Activity

Terahertz Permittivity of Pressed ZnO and CuO Powder in Polyethylene Pellets: Effect of Porosity

Low Voltage Graphene-Based Amplitude Modulator for High Efficiency Terahertz Modulation

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