Ferromagnetic tunnel junction element exhibiting high magnetoresistivity at finite voltage and tunnel magnetoresistive head provided therewith, magnetic head slider, and magnetic disk drive

A tunnel magnetoresistive head comprising:

• a magnetoresistive element having a tunnel insulating layer, first and second ferromagnetic layers arranged on both sides of said tunnel insulating layer, a first noble metal layer formed between said tunnel insulating layer and said first ferromagnetic layer, and a second noble metal layer formed between said tunnel insulating layer and said second ferromagnetic layer,
• magnetic shield layers formed on both sides of said magnetoresistive element, and
• a pair of electrodes to apply drive current to said magnetoresistive element,
• wherein said first and second ferromagnetic layers are comprised of Co or CoxFe1-x (x=0.8–1.0), and
• wherein a region of the magnetoresistive element operating voltage is from 0.01 V to 0.1 V.

A tunnel magnetoresistive head comprising:

• a magnetoresistive element having a tunnel insulating layer, first and second ferromagnetic layers arranged on both sides of said tunnel insulating layer, a first noble metal layer formed between said tunnel insulating layer and said first ferromagnetic layer, and a second noble metal layer formed between said tunnel insulating layer and said second ferromagnetic layer,
• magnetic shield layers formed on both sides of said magnetoresistive element, and
• a pair of electrodes to apply drive current to said magnetoresistive element,
• wherein said first and second ferromagnetic layers are comprised of Fe, and
• wherein a region of the magnetoresistive element operating voltage is from 0.01 V to 0.15V.

A tunnel magnetoresistive head comprising:

• a magnetoresistive element having a tunnel insulating layer, first and second ferromagnetic layers arranged on both sides of said tunnel insulating layer, a first noble metal layer formed between said tunnel insulating layer and said first ferromagnetic layer, and a second noble metal layer formed between said tunnel insulating layer and said second ferromagnetic layer,
• wherein magnetic shield layers are formed on both sides of said magnetoresistive element,
• wherein a pair of electrodes applies drive current to said magnetoresistive element,
• wherein said first and second ferromagnetic layers are comprised of Fe, and
• wherein a region of the magnetoresistive element operating voltage is from 0.3V to 0.7 V.

A tunnel magnetoresistive head comprising:

• a magnetoresistive element having a tunnel insulating layer, first and second ferromagnetic layers arranged on both sides of said tunnel insulating layer, a first noble metal layer formed between said tunnel insulating layer and said first ferromagnetic layer, and a second noble metal layer formed between said tunnel insulating layer and said second ferromagnetic layer,
• magnetic shield layers formed on both sides of said magnetoresistive element, and
• a pair of electrodes to apply drive current to said magnetoresistive element,
• wherein said first and second ferromagnetic layers are comprised of NixFe1-x (x=0.8–1.0), and
• wherein a region of the magnetoresistive element operating voltage is from 0.03 V to 0.06 V.