Read-write magnetic transducer having a composite structure comprising a stack of thin films

Claim 2

A READ/WRITE TRANSDUCER COMPRISING: A PAIR OF MAGNETIC POLE-PIECES AND READ-WRITE CONDUCTOR MEANS INDUCTIVELY COUPLED TO SAID POLE-PIECES AND PASSING THEREBETWEEN, EACH POLEPIECE INCLUDING THE SUPERPOSITION OF: A FIRST MAGNETIC LAYER MEMBER CLOSE TO SAID CONDUCTOR MEANS, A MAGNETOSTATICALLLY DECOUPLING LAYER MEANS, OVER SAID FIRST MAGNETIC LAYER MEMBER, AND A SECOND MAGNETIC LAYER MEMBER OF SUBSTANTIALLY LOWER PERMEABILITY, SUBSTANTIALLY HIGHER SATURATION FLUX DENSITY AND APPRECIABLY HIGHER VALUE OF ANISTROPY FIELD THAN SAID FIRST MAGNETIC LAYER MEMBER.

Claim 3

A read/write transducer according to claim 1, wherein said magnetostatically decoupling layer means is comprised of a non-magnetic dielectric material.

Claim 4

A read/write transducer according to claim 1, wherein said magnetostatically decoupling layer means comprises a stack of thin films of alternating magnetic materials one of which is of substantially lower permeability, substantially higher saturation flux density and appreciably higher value of anisotropy than the other one.

Claim 5

A read/write transducer according to claim 1, wherein said first magnetic layer member consists of a stack of relatively insulated thin magnetic films.

Claim 6

A read/write transducer according to claim 4, wherein said second magnetic layer member also consists of a stack of relatively insulated thin magnetic films.

Claim 7

A read/write transducer according to claim 1, wherein the material of said first magnetic layer member is an iron-nickel alloy and the material of said second magnetic layer member is selected from the group consisting of iron, cobalt and the iron-cobalt alloys.

Claim 8

In a read/write magnetic transducer comprising a pair of magnetic pole-pieces and read-write conductor means inductively coupled to the pole-pieces and passing therebetween, a composite pole-piece structure comprising a stack of magnetic maTerial thin films wherein a first plurality of said films close to the said conductor means are relatively insulated and of a first magnetic material, a second plurality of said films over the first plurality are directly contacting each other and alternate first and second magnetic materials, and a third plurality of said films are relatively insulated and of the said second magnetic material over the second plurality of thin films, and wherein the said second magnetic material is of substantially lower permeability, substantially higher saturation flux density and appreciably higher value of anisotropy field than the first magnetic material.

Claim 9

In a read/write magnetic transducer comprising a pair of magnetic pole-pieces and read-write conductor means inductively coupled to the pole-pieces and passing therebetween, a composite pole-piece structure comprising a stack of magnetic maTerial thin films wherein a first plurality of said films close to the said conductor means are relatively insulated and of a first magnetic material, a second plurality of said films over the first plurality are directly contacting each other and alternate first and second magnetic materials, and a third plurality of said films are relatively insulated and of the said second magnetic material over the second plurality of thin films, and wherein the said second magnetic material is of substantially lower permeability, substantially higher saturation flux density and appreciably higher value of anisotropy field than the first magnetic material.

Claim 10

In a read/write magnetic transducer comprising a pair of magnetic pole-pieces and read-write conductor means inductively coupled to the pole-pieces and passing therebetween, a composite pole-piece structure comprising a first plurality of relatively insulated thin film of a first magnetic material close to said read-write conductor means, a nonmagnetic dielectric material layer over first plurality of thin films, and a second plurality of relatively insulated thin films of a second magnetic material over said dielectric layer, the second magnetic material being of substantially lower permeability, substantially higher saturation flux density and appreciably higher value of anisotropy field than the first magnetic material.

Claim 11

In a read/write magnetic transducer comprising a pair of magnetic pole-pieces and read-write conductor means inductively coupled to the pole-pieces and passing therebetween, a composite pole-piece structure comprising a first plurality of relatively insulated thin film of a first magnetic material close to said read-write conductor means, a nonmagnetic dielectric material layer over first plurality of thin films, and a second plurality of relatively insulated thin films of a second magnetic material over said dielectric layer, the second magnetic material being of substantially lower permeability, substantially higher saturation flux density and appreciably higher value of anisotropy field than the first magnetic material.