Magnetic head comprising a multilayer magnetoresistive device and a yoke for introducing magnetic flux from a medium to the magnetoresistive device

A magnetic head comprising:

• a magnetoresistive device including a laminate structure in which a non-magnetic layer is interposed between a first magnetic layer and a second magnetic layer,
• a yoke for introducing an external magnetic field from a medium to the magnetoresistive device via a magnetic gap;
• a current introducing part for allowing current to flow between the first magnetic layer and the second magnetic layer via the non-magnetic layer;
• a measuring part for detecting a change in resistance occurring between the first magnetic layer and the second magnetic layer in accordance with a relative magnetization angle between the first magnetic layer and the second magnetic layer that is changed by the external magnetic field induced via the yoke;
• and
• a substrate over which the magnetoresistive device and the yoke are formed,
• wherein, the yoke and the magnetoresistive device are arranged so as to overlap each other, when viewed from a direction perpendicular to a yoke plane,
• when an area of the non-magnetic layer is defined as a device cross-section area and an area of the yoke is defined as a yoke area, viewed along a direction perpendicular to a surface of the substrate, then the device cross-section area is not less than 30% of the yoke area, and
• a magnetic flux path formed by the external magnetic field introduced from the magnetic gap to the magnetoresistive device appears as a loop passing through the yoke and the medium when viewed from the direction perpendicular to the yoke plane.