Temperature dependent anisotropy and linewidth in the high-Q ferrimagnet V(TCNE)x
Year: 2020
Type: preprint
Abstract: The search for low-loss magnetic materials, traditionally driven by applications in microwave electronics, has gained new urgency and additional constraints from emerging applications in quantum information science and technology. While yttrium iron garnet (YIG) has been the material of choice for decades, the emergence of molecule-based materials with robust magnetism and ultra-low damping has opened new avenues for exploration. Specifically, thin-films of vanadium tetracyanoethylene (V[TCNE]x) have shown room-temperature Gilbert damping that rivals the intrinsic (bulk) damping of polished YIG spheres (alpha = 4 x 10^-5). Here, we present a comprehensive and systematic study of the low-temperature magnetization dynamics for V[TCNE]x thin-films, revealing a temperature-driven, strain-dependent magnetic anisotropy that compensates the thin-film shape anisotropy, and the recovery of magnetic resonance linewidth at 5 K comparable to room-temperature values (roughly 2 G at 9.4 GHz). We can account for the variations of the V[TCNE]x linewidth within the context of scattering from dilute paramagnetic impurities.
Source: arXiv (Cornell University)
Institutions: The Ohio State University, Cornell University, University of Iowa
Language: English
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W3082197067