Researchers at NIST have developed a new type of magnetic material that significantly improves the sensitivity of magnetic sensors. This material is made by layering a magnetic alloy with thin layers of silver, creating a “magnetic sandwich.” This design reduces internal stress in the magnetic film, which makes the material more responsive to small magnetic fields. The result is a 400-fold improvement in sensitivity in some cases, which could lead to better sensors for uses like medical devices, weapons detection, and data storage.
The improvement comes from the way the silver layers affect the structure of the magnetic material. Instead of forming many small, stressed grains, the material forms larger, less stressed grains. This reduces the saturation field—the amount of magnetic field needed to fully magnetize the material—making the sensors more sensitive. The discovery could help in creating more efficient flux concentrators, which are used to amplify magnetic fields in compact sensors. This research was published in the *Journal of Applied Physics* in 2009.
Source: https://www.nist.gov/news-events/news/2009/01/taking-stress-out-magnetic-field-detection
Keywords: magnetic sensors, saturation field, flux concentrators
