Patent ID: 7760473

Claim:
A magnetic detection device, comprising: a fixed magnetic layer having a fixed magnetization; and a free magnetic layer being formed on the fixed magnetic layer with a non-magnetic material layer interposed therebetween and having a magnetization varied by an exterior magnetic field, wherein the fixed magnetic layer has a laminated ferri-structure including a first fixed magnetic layer, a second fixed magnetic layer, and a non-magnetic intermediate layer interposed therebetween, and the second fixed magnetic layer contacts the non-magnetic material layer, wherein a part of the second fixed magnetic layer is formed of a first Heusler-alloy layer represented in a formula Co 2x (Mn (1-z) Fe z ) x α y (where an element α is an element selected from 3B group, 4B group, and 5B group of the old International Union of Pure and Applied Chemistry periodic table of the elements, x and y are in the unit of at %, and 3x+y=100 at %), and wherein the content y is in the range of about 20 to 30 at % and a Fe ratio z in MnFe is in the range of about 0.2 to 0.8.