Magnetoresistance effect element comprising nano-contact portion not more than a fermi length, and magnetic head utilizing same

A magnetoresistance effect element comprising:

• a substrate;
• a layer lamination structure disposed on the substrate and comprising a buffer layer, a free layer composed of a ferromagnetic layer, an insulating layer including at least one nano-contact portion having a dimension of not more than Fermi length, a pinned layer and an anti-ferromagnetic layer, which are laminated in the described order on the substrate;
• side insulating layer disposed on both side portions of the layer lamination structure;
• and domain stability layers disposed on both side portions of the layer lamination structure through the side insulating layer, respectively,
• said pinned layer being composed of a first ferromagnetic layer, a non-magnetic layer and a second ferromagnetic layer disposed in this order on the side of the insulating layer, and said domain stability layer being composed of a ferromagnetic layer and an anti-ferromagnetic layer;
• said free layer having a same direction of magnetization as that of the ferromagnetic layer constituting the domain stability control layer.

A magnetic head comprising:

• a magnetoresistance effect element;
• electrodes disposed on both sides of the magnetoresistance effect element;
• and
• a pair of shield members disposed on outside surfaces of the electrodes, respectively,
• said magnetoresistance effect element comprising:
• a substrate;
• and a layer lamination structure disposed on the substrate and comprising a buffer layer, an anti-ferromagnetic layer, a pinned layer, an insulating layer including at least one nano-contact portion having a dimension of not more than Fermi length, a free layer composed of a ferromagnetic layer and a domain stability layer, which are laminated in the described order on the substrate, wherein said pinned layer is composed of a first ferromagnetic layer, a non-magnetic layer and a second ferromagnetic layer disposed in this order on the side of the anti-ferromagnetic layer, and said magnetic stability control layer is composed of a non-magnetic layer, a ferromagnetic layer and an anti-ferromagnetic layer disposed in this order from the side of the free layer.

A magnetic head comprising:

• a magnetoresistance effect element;
• electrodes disposed on both sides of the magnetoresistance effect element;
• and
• a pair of shield members disposed on outside surfaces of the electrodes, respectively,
• said magnetoresistance effect element comprising:
• a substrate;
• a layer lamination structure disposed on the substrate and comprising a buffer layer, a free layer composed of a ferromagnetic layer, an insulating layer including at least one nano-contact portion having a dimension of not more than Fermi length, a pinned layer and an anti-ferromagnetic layer, which are laminated in the described order on the substrate;
• side insulating layer disposed on both side portions of the layer lamination structure;
• and domain stability layers disposed on both side portions of the layer lamination structure through the side insulating layer, respectively, wherein said pinned layer is composed of a first ferromagnetic layer, a non-magnetic layer and a second ferromagnetic layer disposed in this order on the side of the insulating layer, and said magnetic stability control layer is composed of a ferromagnetic layer and an anti-ferromagnetic layer.