DYNAMIC OBSERVATION OF MAGNETIC DOMAINS BY ONLINE REAL-TIME ELECTRON HOLOGRAPHY

Dynamic behavior of magnetic domains in a thin permalloy film has been observed by on-line real-time electron holography. Electron holograms formed in a transmission electron microscope equipped with an electro n biprism are detected by a TV camera and transferred to a liquid-crys tal spatial light modulator (LC-SLM) located at the output port of a M ach-Zehnder interferometer. Interference micrographs, where magnetic f lux lines are directly visualized, are obtained by superimposing a pla ne wave onto an object wave reconstructed from the hologram in the LC- SLM. Using this system, dynamic behavior of magnetic domains in the ma gnetization or demagnetization processes is clearly observed.