Strain measurement in ferromagnetic crystals using dark-field electron holography

This study proposes a method to separate thegeometric phase shift due to lattice strain from the undesired phase information, resulting frommagnetic fields that are superposed in the dark-fieldelectron holography (DFEH) observations. Choosing a distinct wave vector for the Bragg reflection reversed the sense of thegeometric phase shift, while the sense of the magnetic information remained unchanged. In the case of an Nd-Fe-B permanent magnet, once the unwanted signal was removed by data processing, the residual phaseimage revealed a strain map. Even though the applications of DFEH have thus far been limited tonon-magnetic systems, the method proposed in this work is also applicable tostrain measurements in variousferromagnetic systems.

Source: Applied Physics Letters - November 7, 2016 Category: Physics Authors: Yasukazu Murakami, Kodai Niitsu, Syuhei Kaneko, Toshiaki Tanigaki, Taisuke Sasaki, Zentaro Akase, Daisuke Shindo, Tadakatsu Ohkubo and Kazuhiro Hono Source Type: research