Effect of oxygen ion irradiation on dielectric, structural, chemical and thermoluminescence properties of natural muscovite mica

Improved Working Temperature and Capacitive Energy Density of Biaxially Oriented Polypropylene Films with Alumina Coating Layers

“…However, with further increasing the thickness of the Al 2 O 3 layer, the defects, surface buckles, and even microcracks will appear during the longtime sputtering; 52 these complicated impact factors should degrade the dielectric constants of the composite films. 53 When the temperature gradually increases to 125 °C, the values of ε r decrease, consistent with earlier reports on BOPPbased composites and other nonpolar polymers. 54,55 Interestingly, because of the nonpolar nature of BOPP, 56 Figure 2d shows the percentage of ε r enhancement compared with the pure BOPP at 1 kHz.…”

“…The dielectric constant and the dissipation factor at 1 kHz for a pure BOPP film at 20 °C are 2.21 and 1.29 × 10 –3 , respectively, consistent with earlier reports. − Due to the dielectric constant of Al 2 O 3 (∼9.0) , higher than BOPP (∼2.21) and the interfacial polarizations possibly existing at the interfaces between BOPP and Al 2 O 3 layers, , the dielectric constant of composite films increases to a higher value of ∼2.39 when the thickness of the Al 2 O 3 layer increases to ∼270 nm (sample ID: AO/BOPP/AO-270). However, with further increasing the thickness of the Al 2 O 3 layer, the defects, surface buckles, and even microcracks will appear during the longtime sputtering; these complicated impact factors should degrade the dielectric constants of the composite films . When the temperature gradually increases to 125 °C, the values of ε r decrease, consistent with earlier reports on BOPP-based composites and other nonpolar polymers. , Interestingly, because of the nonpolar nature of BOPP, the dissipation factors of Al 2 O 3 /BOPP/Al 2 O 3 films remain very low (3.1 × 10 –4 ∼ 1.8 × 10 –3 at 1 kHz) from 20 to 125 °C, and coating Al 2 O 3 layers has no obvious influence on the dissipation factors.…”

Naturally occurring van der Waals materials

“…The mica family is formed by very closely related layered silicates such as muscovite (with formula KAl 2 (AlSi 3 )O 10 (OH) 2 ), biotite (with formula K(Mg,Fe) 3 (AlSi 3 )O 10 (OH) 2 ), lepidolite (with formula K(Li,Al) 2-3 (AlSi 3 )O 10 (OH) 2 ), and phlogopite (with formula KMg 3 (AlSi 3 )O 10 (OH) 2 ). Most of the previous works on exfoliated micas are focused on muscovite mica, a wide band insulator (5.1 eV of direct gap) with a large dielectric constant (~10) in its bulk form 131,132 . The exfoliation of layered materials with stronger interlayer forces has rarely been reported and mica is one of these few cases.…”

“…Most of the previous works on exfoliated micas are focused on muscovite mica, a wide band insulator (5.1 eV of direct gap) with a large dielectric constant (~10) in its bulk form. 133,134 The exfoliation of layered materials with stronger interlayer forces has rarely been reported and mica is one of these few cases. In fact, muscovite mica has been successfully exfoliated down to a single-layer by mechanical exfoliation and their optical properties 10,12 as well as their mechanical properties have been studied finding an optical method to determine its thickness and a Young's modulus of ~200 GPa, higher than that of bulk muscovite (~175 GPa).…”

Complex Electrical Conductivity of Biotite and Muscovite Micas at Elevated Temperatures: A Comparative Study

“…Because of these superior dielectric characteristics, the electrical and dielectric properties of micas have been extensively investigated in the past few decades, although many of them focused mainly on high electric field measurements [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. The interest is still undiminished due to the modified structural and dielectric properties of micas upon irradiation and the fact that they combine high working temperature and flexibility as dielectric materials, making them potential candidates for high-temperature energy storage applications [ 26 , 27 , 28 , 29 ]. Other peculiar applications concern the use of mica as a potential gate dielectric in organic field-effect transistors (OFETs), as a substrate for biological samples preparation for high resolution microscopy and in the assembly of macroscopic biomimetic polymeric mica films [ 30 , 31 , 32 , 33 ].…”