The Electromagnetic Absorption of a Na-Ethylenediamine Graphite Intercalation Compound

Abstract

A sodium-ethylenediamine graphite intercalation compound (Na­(ethylenediamine)­C15: “GIC”) made from graphite flakes was used to study the microwave absorption performance of a GIC for the first time. Compared with the pristine graphite flakes, the neighboring layers in this GIC are pillared by Na­(ethylenediamine)+ and possess a larger layer distance and improved electrical conductivity. Owing to the electrical conductivity of this GIC, only half of the loading content, compared to graphite flakes, is needed to achieve an outstanding absorption of −75.6 dB at 9.25 GHz (10.0 wt % GIC in paraffin in a 4.0 mm thick sample), but for graphite, 20.0 wt % is required for an absorption of −37.6 dB.

Essential geometric and electronic properties in stage-n graphite alkali-metal-intercalation compounds

“…Li, Na, K and Rb, are well-know as are some molecular clusters, e.g. AlCl4, N2O5, Na(ethylenediamine)C5 28 . The interlayer distances between neighboring carbon layers will depend on the species of intercalations, for instance, the distances are 3.76 Å and 5.65 Å for, respectively, Li atoms and Rb atoms 8 .…”

Intercalation as a versatile tool for fabrication, property tuning, and phase transitions in 2D materials

“…Superconductivity and CDW in 2H- TaSe electrical conductivity and induces polarization; thus, increasing microwave absorption ability of graphene (Fig. 5d-f) 165 .…”

“…Intercalation of Na and ethylenediamine partially fills the π* bands and increases electrical conductivity and induces polarization; thus, increasing microwave absorption ability of graphene (Fig. 5d-f) 165 .…”

“…Such reversibility indicates that the gateintercalated ions do not chemically react (that is, form chemical 161 . c, d Sodium-ethylenediamine GIC Na (ethylenediamine)C15: "GIC" possess higher electrical conductivity and unfrom 1.0-5.0 mm with loadings of 10.0 wt% 165 . Panel a adapted with permission ref.…”

“…Optical transmission image of an 8-nm thick Bi 2 Se 3 nanoplate before (bottom-left) and after (bottom-right) Cu intercalation.Schematic showing the BM shift induced by the increased free electron density (bottom-center)161 . c, d Sodium-ethylenediamine GIC Na (ethylenediamine)C15: "GIC" possess higher electrical conductivity and unfrom 1.0-5.0 mm with loadings of 10.0 wt%165 . Panel a adapted with permission ref 57.…”