Researchers from the National Institute of Standards and Technology (NIST), IBM, and the Massachusetts Institute of Technology, have pushed the measurement of thin films to the edge to produce the first data on how the edges of metallic thin films contribute to their magnetic properties. The results may impact the design of future nanoscale electronics.
Ferromagnetic thin films of metallic materials are layered in patterns on a substrate (such as silicon) during the manufacture of microelectronic devices that use magnetic properties, such as computer hard drives. While methods for measuring the magnetic properties of ferromagnetic thin films already exist, currently there is not a way to define those properties for the edges of the film. As microelectronic components get smaller, these edges become a larger fraction of the surface.
The team demonstrated a spectroscopic technique for measuring the magnetic properties of the edges of nickel-iron alloy thin films patterned in an array of parallel nanowires on top of a silicon disk. They beamed microwaves of different frequencies over the stripes and measured the magnetic resonances that resulted. They were able to determine which data and which magnetic behaviors were attributable to the edge.