Low-damping magnetic materials in FM-NM-FM structures on flexible substrates for RF/microwave applications

New magnetic materials can open a way for energy-efficient and flexible antenna and RF microwave devices. Low damping magnetic materials have been attributed to single-crystal magnetic insulators. High-quality with low damping magnetic materials, are deposited on flexible substrates, are needed to enhance the performance of flexible devices. Here, we demonstrated low magnetic damping in a ferromagnetic (FM)/non-magnetic(NM)/ferromagnetic(FM) structure fabricated on a flexible Mica substrate, which comparable with the one found in solid structures. With different Ru thickness, the two FM layers shows parallel(P) and antiparallel(AP) interaction, which is called the Ruderman–Kittel–Kasuya–Yosida (RKKY) interaction. For an AP coupling, the linewidth demonstrates a different behavior. For low external fields (and low frequencies in the range 4GHz – 6GHz) the linewidth is practically independent with the frequency, which shows great potential applications for RF/microwave devices and antenna.