Heterogeneous spacers for CPP GMR stacks

A current-perpendicular-to-plane (CPP) giant magnetoresistive (GMR) read/write head comprising:

• a) a first shield;
• b) a first conductive gap adjacent to the first shield;
• c) a second shield;
• d) a second conductive gap adjacent to the second shield;
• and
• e) a CPP magnetoresitive sensor disposed between the first and second conductive gaps;
• wherein the CPP magnetoresistive sensor comprises:
• i) at least two magnetic layers;
• and
• ii) at least one heterogeneous spacer layer disposed between the two magnetic layers, wherein the heterogeneous spacer layer is made of a heterogeneous material which is composed of conductive grains within a highly resistive matrix, the content of the conductive grains in the heterogeneous spacer layer being between about 0.1 volume % and about 50 volume %.

A disk drive comprising:

• a) a magnetic recording disk;
• b) a current-perpendicular-to-plane (CPP) giant magnetoresistive (GMR) read/write head including a CPP magnetoresistive sensor;
• c) an actuator connected to the CPP GMR read/write head for moving the CPP GMR recording head across the magnetic recording disk;
• d) a mechanism connected to the magnetic recording disk for moving the magnetic recording disk relative to the CPP GMR read/write head;
• wherein the CPP magnetoresistive sensor comprises:
• i) at least two magnetic layers;
• and
• ii) at least one heterogeneous spacer layer disposed between the two magnetic layers, wherein the heterogeneous spacer layer is made of a heterogeneous material which is composed of conductive grains within a highly resistive matrix, the content of the conductive grains in the heterogeneous spacer layer being between about 0.1 volume % and about 50 volume %.

A current-perpendicular-to-plane (CPP) magnetoresistive sensor comprising:

• a) at least two magnetic layers;
• and
• b) at least one heterogeneous spacer layer disposed between the two magnetic layers, wherein the heterogeneous spacer layer comprises:
• a layer of conductive material;
• and
• a discontinuous layer of highly resistive material adjacent to the layer of conductive material, wherein holes in the discontinuous layer result in limited current paths for electrons.