Patent ID: 8040641

Claim:
A magneto-resistance effect element comprising a stacked body which comprises a pinned layer having a fixed magnetization direction, a free layer having a magnetization direction that varies according to an external magnetic field, and a nonmagnetic spacer layer which is interposed between said pinned layer and said free layer, said stacked body having a constricted shape in which at least one part of said spacer layer is constricted when viewed from at least one direction perpendicular to a stacked direction of said stacked body, wherein the smallest cross-section area of said spacer layer is smaller than the smallest cross-section area of said pinned layer and smaller than the smallest cross-section area of said free layer when viewed from said stacked direction, and A 1 /A 2 ≧applied voltage/(7×10 7 [A/cm 2 ]×sheet resistance), where A 1 is the largest cross-section area of said free layer when viewed from said stacked direction, and A 2 is the smallest cross-section area of said spacer layer when viewed from said stacked direction.