MEMORY STORAGE DEVICES COMPRISING DIFFERENT FERROMAGNETIC MATERIAL LAYERS, AND METHODS OF MAKING AND USING THE SAME

摘要

A memory storage device that contains alternating first and second ferromagnetic material layers is provided. Each first ferromagnetic material layer has a first layer thickness (L₁) and a first critical current density (JC₁), and each second ferromagnetic material layer has a second layer thickness (L₂) and a second critical current density (JC₂), provided that JC₁2, L₁ is greater than about 300 nm, and L₂ ranges from about 20 nm to about 200 nm. The device further comprises alternating magnetic domains of opposite directions that are separated by domain walls. The magnetic domains and domain walls are movable across the first and second ferromagnetic material layers upon application of a driving current. Correspondingly, data can be stored in the memory storage device as locations of the magnetic domains and domain walls.