Three pioneering instruments developed by NIST’s Physical Measurement Laboratory (PML) are now on display at the agency’s Advanced Measurement Laboratory in Gaithersburg, Maryland. These instruments were crucial in advancing the understanding of surface magnetism and electronic structure in the 1970s and 1980s.
The first instrument, a spin-polarized electron gun, was developed in the 1970s. It generated a high-intensity beam of electrons with uniform spin direction, providing a sensitive probe of spin-dependent magnetic interactions at material surfaces. The gun was mounted at standing height with a tennis ball attached to prevent head injuries.
In the early 1980s, PML scientists developed a compact spin analyzer that could be easily attached to a scanning electron microscope. This combination created a powerful technique called scanning electron microscopy with polarization analysis, which significantly improved the ability to discern fine magnetic microstructure details on surfaces.
The third instrument, a scanning tunneling microscope (STM), was built by PML scientists in 1984. STMs use quantum tunneling to create atomic-scale maps of surface structure. The NIST STM, one of the first in the U.S., has taken on added significance as the original IBM STM it was based on was accidentally destroyed.
These instruments represent significant milestones in the development of surface characterization techniques that have had a lasting impact on various fields of science and technology.
Keywords: Electron, Spin, Tunneling, Microscope, Nanoscale
