2019 年 3 巻 1 号 p. 24-27
Ring samples are often used for measuring the DC magnetic characteristics of magnetic material. In this measuring method, stress and strain are induced into a specimen by winding coils on the ring samples. The magnetic characteristics of the samples might be affected by the inverse-magnetostriction phenomenon, which is caused by compressive stress on the ring samples. Hence, by using ring sample of a material with a positive magnetostriction constant, DC magnetic characteristics were measured both with and without the polymer case in order to prevent winding stress. As a result, it was confirmed that the magnetic characteristics of the ring samples were changed by the inverse-magnetostrictive effect induced by compressive stress.