This magnetic microscope and algorithm uses one-dimensional magnetic field measurements to produce full 3D vector maps of magnetic fields emanating from devices. The ability to accurately measure and map the stray magnetic fields from devices is important for research, production, quality control, and process troubleshooting. Direct measurement of all three axes of the magnetic vector field is typically, time-consuming, costly, or technologically challenging, especially for microscale devices where high spatial resolution is required. University of Florida researchers have developed a 3D magnetic field reconstruction algorithm that can be used to calculate a multidimensional vector field using data from only one dimension of the field. The system can determine both the x- and y-components of the field accurately and efficiently using measurements from only the z-component of the field with a spatial resolution down to four micrometers. This approach is primarily targeting the stray magnetic fields from microscale devices, such as magnetic actuators, magnetic microsystems, hard disk read/write heads, magnetic memory, magneto-meters, integrated circuits, and other microelectronic devices. However, the algorithm is applicable across all size scales.
Allows user to produce a 3D vector field map from 1D measurements
This measurement system and algorithm quantitatively map the stray magnetic fields from magnetic structures. The magnetic field imaging uses an upright reflective polarizing light microscope outfitted with specialized magnetic field indicator films. It makes measurement “slices” at increasing heights; each slice is only sensitive to a single component of the magnetic field, such as the z-axis. The 1-D magnetic field input data may come from Hall probe, magneto-optical imaging, magnetic force microscopy, or other measurement approaches. Researchers then reconstruct the other magnetic field components, the x- and y-components, using a special signal processing method. Using a variation of Gauss’s Law for magnetism, researchers can produce accurate and noise-free 3D magnetic field maps, even when using noisy initial measurements.