2023 年 7 巻 2 号 p. 108-111
We have been studying strain sensors based on the inverse magnetostriction effect. In our previous research, we evaluated the sensitivity characteristics of an entire strain sensor by measuring the change in the direction of magnetic anisotropy when strain was applied to the sensor as an impedance change using a network analyzer. When a directional change in magnetic anisotropy occurs simultaneously across the entire sensor when strain is applied to the sensor, the impedance change becomes steeper, and the sensitivity improves. Therefore, in this study, the change in local magnetic anisotropy due to the inverse magnetostriction effect that occurs when strain is applied to the sensor was obtained from a local BH loop obtained using the Kerr effect, and the uniformity of the local magnetic anisotropy was evaluated. As a result, it was confirmed that the magnetic anisotropy varied from place to place when stress was applied. Since quantitative evaluation of local magnetic anisotropy and strain was possible through local BH loop measurement using a Kerr effect microscope, this measurement could be used to further increase the sensitivity of the sensor.
