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Nanomagnetism at NIST: Magnetic Nanostructures
Magnetic nanostructures have a variety of applications ranging from electronic devices like hard disk drive read heads to patterned magnetic bits for storing information. The performance of these applications depends crucially on their nanoscale magnetic properties. NIST has a number of programs measuring these properties and is developing the future techniques used to measure them. The static domain patterns are imaged through a variety of techniques and the dynamics of structures are measured through a different set of techniques.
NIST has a number of programs to fabricate magnetic nanostructures. Frequently, these are studied in the context of developing the ability to measure the important properties of related devices. For example, patterned media are typically made from hard magnetic materials whereas sensors are made from soft magnetic materials. "Hard" and "soft" refer to the ease with which the magnetization can be changed. Test structures of patterned media are measured to develop techniques to reduce the variability from bit to bit. Several groups (A, B, C) are fabricating test structures from soft magnetic materials to understand how magnetic properties change as devices get smaller and how the edges control the magnetization dynamics for nanoscale structures. Several programs fabricate magnetoelectronic devices, including current-controlled oscillators, which are fabricated from 40 nm nanocontact structures, and magnetic tunnel junctions, which are fabricated into sensor structures.