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SUMMARY:Shielding with Graphene Epoxy Composites in the Extended THF Band 
 from 0.25 to 4.00 THz
DTSTART;VALUE=DATE-TIME:20220706T140500Z
DTEND;VALUE=DATE-TIME:20220706T142000Z
DTSTAMP;VALUE=DATE-TIME:20260309T052728Z
UID:indico-contribution-745@events.ncbj.gov.pl
DESCRIPTION:Speakers: Kamil Stelmaszczyk (CENTERA Laboratories\, Institute
  of High Pressure Physics PAS\, Warsaw\, Poland)\nWe report on THz charact
 erization of graphene composites in the extended THF band from 0.25 to 4.0
 0 THz. The composites\, containing low percent by weight fractions (wt.%) 
 of graphene form 0.8wt.% to 1.2wt.%\, were investigated using THz- Time Do
 main Spectroscopy (THz-TDS). Based on the measured transmission and reflec
 tion coefficients\, the shielding effectiveness parameters of reflection (
 SER) and transmission (SET) were calculated to determine the shielding eff
 ectiveness of absorption (SEA). The procedure comprised each of the weight
  fractions of graphene.\nWhile the SER was found to be less than ~0.6 dB w
 ithin the measured frequency range and for all the samples\, the SET and S
 EA were found to be substantially higher\, firmly above ~70 dB with graphe
 ne loading of 1.2wt.% at the frequency f=1.6 THz. Such unexpectedly high t
 otal shielding effectiveness resulted mostly from absorption\, due to the 
 measured low absolute values of SER.\nThe fact that a simple EM energy red
 irection via conduction-based reflection was not primary energy loss mecha
 nism is favorable from the point of view of EMI shielding because contrary
  to metal-based conducting coatings or metallic nanocomposites\, the graph
 ene-based epoxy materials do not spread unwanted EM radiation from one pla
 ce to another. Additionally\, they have low weights.\nBy performing the Be
 er-Lambert calculations\, we show that even a thin-film or a spray coating
  with a thickness in the few-hundred-micrometer range of lightweight\, not
  conducting and not reflecting graphene epoxy composites can be sufficient
  for blocking THz radiation in many practical applications\, where the shi
 elding of EM by ~20–30 dB is typically sufficient. Thus\, the fabricated
  composites can be successfully used as effective ultra-thin stealth mater
 ials.\n\n[1]. Z. Barani\, K. Stelmaszczyk\, et al.\, Appl. Phys. Lett. 120
 \, 063104 (2022)\n\nhttps://events.ncbj.gov.pl/event/75/contributions/745/
LOCATION:Novotel Warszawa Centrum Róża
URL:https://events.ncbj.gov.pl/event/75/contributions/745/
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