Magnetoresistive element with free-layer and method of manufacturing same

A magnetic multi-turn sensor comprising one or more giant magnetoresistive elements, each giant magnetoresistive element comprising:

• a reference layer;
• a non-magnetic layer adjacent to the reference layer;
• and
• a free-layer of ferromagnetic material, wherein the free-layer comprises a first layer of ferromagnetic material adjacent to the non-magnetic layer, and a multi-layer arrangement at least comprising a plurality of layers of a first material, the first material being ferromagnetic, and a plurality of layers of a second material,
• wherein a thickness of the free-layer is greater than 30 nm, and
• wherein the plurality of layers of the first material have a first magnetostriction and the plurality of layers of the second material have a second magnetostriction that reduces magnetostriction of the free-layer.

A method of manufacturing a giant magnetoresistive element, wherein the method comprises:

• forming a reference layer;
• forming a non-magnetic layer adjacent to the reference layer;
• and
• forming a free-layer of ferromagnetic material, wherein the free-layer comprises a first layer of ferromagnetic material adjacent to the non-magnetic layer, and a multi-layer arrangement at least comprising a plurality of layers of a first ferromagnetic material, the first material being ferromagnetic, and a plurality of layers of a second material,
• wherein a thickness of the free-layer is greater than 30 nm, and
• wherein the plurality of layers of the first ferromagnetic material have a first magnetostriction and the plurality of layers of the second material have a second magnetostriction that reduces magnetostriction of the free-layer.