Magnetic Nanoislands in a Morphotropic Cobaltite Matrix

摘要

High-density magnetic memories are essential components for spintronics,quantum computing, and energy-efficient electronics. Miniaturization ofmagnetic storage units requires reduced dimensionality and magnetic domainstability at the nanoscale. However, inducing magnetic order and selectivelytuning spin-orbital coupling at specific locations is challenging. Here, anunprecedented approach is demonstrated to construct switchable magneticnanoislands in a nonmagnetic matrix based on cobaltite homostructures. Themagnetic and electronic states are laterally modified by epitaxial strain, whichis regionally controlled by freestanding membranes. Tensile-strained cobaltitelayers exhibit ferromagnetic properties, while compressively strained cobaltitelayers exhibit a small magnetic response to applied fields. The minimum sizeof magnetic nanoislands reaches ≈35 nm in diameter, suggesting the highestpossible areal density can reach upto ≈400 Gbit/in~2. This methodologyprovides an ideal platform for precisely controlled read/write schemes andenables scalable and patterned memories on silicon and flexible supports forvarious applications.