Development of Magnetic Nanostructures and Their Composites for Efficacious and Lightweight Millimeter Wave Absorbers

Project Overview

Millimeter (mm)-wave (i.e., 30–200 gigahertz (GHz)) absorbing materials are crucial to protect and secure material, communication, electronic/optical signals, and information from next-generation (5G) telecommunication system and high frequency electronic and superconducting quantum devices by eliminating unwanted electromagnetic interference. However, the development of desirable mm wave absorbers is still an ongoing challenge because of the difficulties of fabricating suitable absorbers in mm regimes, despite their importance in miniaturized high-frequency electronic devices. Here, we have designed and fabricated novel magnetic nanostructures with the goal to realize and demonstrate a highly efficient mm wave absorber. Specifically, we successfully synthesized mm wave absorption tunable magnetic nanomaterials, epsilon-phase iron oxide (ɛ-Fe₂O₃), and their core/shell nanostructures by systematic studies exploring critical reaction parameters and synthesis optimization processes. The resulting absorption loss is significantly more efficient than current existing electromagnetic absorbers, especially in the mm wave region (i.e., over -20 dB in the range of 40 to 120 GHz). Our successful generation and demonstration of mm wave absorbers will significantly improve material, communication, and information security in a new era of revolutionary communication.

Mission Impact

Successful fabricating and demonstrating efficient mm wave absorbers opens the door to controlling electromagnetic interference (EMI) pollution arising from upcoming 5G electronic communication systems such as mobile phones and laptops, automated vehicles, aviation electronics, radars, and military toolkits. Concurrently, expanding upon Lawrence Livermore National Laboratory's core competency of advanced materials and manufacturing, we expect to build expertise in the scale-up synthesis, characterization, and magnetic physics of bimagnetic core/shell nanomaterials and to evaluate these materials' utility for mm wave absorbers. These aims are relevant to Livermore's mission areas of stockpile stewardship, threat reduction from weapons of mass destruction, and multi-domain deterrence, and to other federal agencies such as the Office of Naval Research railgun project, and Defense Advanced Research Projects Agency projects for remote sensing, materials, and communication security, and radar imaging.

Publications, Presentations, and Patents

"Development of magnetic nanostructures and their composites for efficacious and lightweight millimeter wave absorbers," IL-13433, patent submitted (12/4/2019).

"Development of magnetic core/shell nanostructures for 5G mm wave absorbers," 5GX Virtual Summit, 05/27/2020 (presentation).

"Development of magnetic core/shell nanostructures for 5G mm wave absorbers," 65th Annual Conference MMM 2020, Nov. 2–6, 2020.

"Development mm wave absorbers for 5G security," United States Special Operation Command, 12/15/2020 (presentation).

"An Epsilon-Fe2O3 Gyromagnetic Nonlinear Transmission Line for RF Generation and Pulse Compression," IL-13696 (9/15/2021).