Advanced TEM for Characterizing Magnetic Properties in Materials

초록

Electron holography has paved a new way for visualizing and measuring nanoscopic objects and electromagnetic fields that were previously inaccessible employing other techniques. Full use is made of the extremely short wavelength of coherent electrons, enabling electron holography to have a great impact on fields spanning from basic science to technological applications. In this talk, I will present recent achievements in magnetic materials studied by advanced transmission electron microscopy (TEM), with high spatial and phase resolutions of TEM. For example, we can visualize the magnetization distribution at nanometer (nm) scaled regions in not only energy-related materials (Fe-Co-Si helimagnet and Nd-Fe-B permanent magnet) but also structural materials (Fe-Al alloy) [1-3]. The methodology presented here, electron holography and Lorentz microscopy, is very promising for visualizing and quantitatively characterizing magnetic properties on the nm scale with ongoing miniaturization and complexity of electronic devices.