Spintronics XIV | 2021
XY dipolar macrospins on curved surfaces forming ferromagnetic liquid droplets
Abstract
Magnetic micro and nanostructures resembling macrospins have, to date, been lithographically patterned and fixed to a predefined 2D or, most recently, 2.5D layout. I will present an alternate route facilitating interfacial self-assembly and jamming of superparamagnetic nanoparticles at curved liquid-liquid interfaces to create macrospin systems. The mechanical jamming of superparamagnetic nanoparticles is key to freeze both structural and magnetic short-range order and transform the paramagnetic ensemble into a ferromagnetic systems with remanent magnetization and rigid microscopic shape. We use hydrodynamics experiments to probe how the magnetization of ferromagnetic liquid droplets and their response to external stimuli can be tuned by chemical, structural and magnetic means. Numerical modeling using molecular dynamics and mircomagnetic simulations, usher a path toward nanopatterning structured liquids.