Answers are grounded in this paper and cite their sources.
Tunable negative permittivity in the radio frequency range has been obtained by percolative Fe₇₈Si₉B₁₃/epoxy composites.
No takes yet. Share an insight, caveat, or question.
Hou et al. (2015) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: