Explanation
When ferromagnetism material is magnetize, its length will stretch or shorten along the magnetize direction. This effect can be used as magnetostriction coefficient λ To represent. furthermore λ The value of is equal to the ratio of the elongation along the magnetize direction to the total length, and the unit is generally ppm. λ＞ 0 represents the dimensional elongation along the magnetize direction, which is called positive magnetostriction, such as iron; On the contrary, it is called negative magnetostriction, such as nickel.
Classification
Fundamental of Material Science -> Performance basis of materials