Magnetic stray fields of patterned permalloy structures investigated by photoemission electron microscopy

Using a photoemission electron microscope we determined magnetic stray fields at the edges of permalloy (Ni80Fe20) particles. X-ray magnetic dichroism was used for visualization of magnetic domains. The values of the stray fields were deduced from the deflection of electrons in the image due to the Lorentz force. The stray fields are responsible for the magnetic interaction of adjacent particles with distances much larger than the thickness. The measured magnetic stray field is about 0.023 T for rectangular particles with a thickness of 30 nm and lateral sizes of tens of microns.