US 2009/0257154 A1 · SCISSORING-TYPE CURRENT-PERPENDICULAR-TO-THE-PLANE GIANT MAGNETORESISTANCE (CPP-GMR) SENSORS WITH DAMPED FREE LAYER STRUCTURES

Abstract

A “scissoring-type” current-perpendicular-to-the-plane giant magnetoresistive (CPP-GMR) sensor has magnetically damped free layers. In one embodiment each of the two free layers is in contact with a damping layer that comprises Pt or Pd, or a lanthanoid (an element selected from the group consisting of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Th, Yb, and Lu). Each of the two free layers has one of its surfaces in contact with the sensor's electrically conducting nonmagnetic spacer layer and its other surface in contact with its associated damping layer. A nonmagnetic film may be located between each free layer and its associated damping layer. In another embodiment the damping element is present as a dopant or impurity in each of the two free layers. In another embodiment a nanolayer of the damping element is located within each of the two free layers.

Claims15

Dependent claims

A magnetoresistive sensor capable of sensing external magnetic fields when a sense current is applied perpendicular to the planes of the layers in the sensor, the sensor comprising:

a substrate;
a first sensing structure on the substrate comprising a first ferromagnetic layer having an in-plane magnetization direction free to rotate in the presence of an applied magnetic field and an element selected from the group consisting of Pt, Pd, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Th, Yb, and Lu;
a nonmagnetic spacer layer on the first ferromagnetic layer;
and
a second sensing structure on the substrate comprising a second ferromagnetic layer on the spacer layer and having an in-plane magnetization direction nonparallel to the first ferromagnetic layer's magnetization direction in the absence of an applied magnetic field and free to rotate in the presence of an applied magnetic field and an element selected from the group consisting of Pt, Pd, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Th, Yb, and Lu.

2 more elements

A scissoring-type current-perpendicular-to-the-plane giant magnetoresistive (CPP-GMR) read head for reading magnetically recorded data from tracks on a magnetic recording medium, the head comprising:

a first shield layer of magnetically permeable material;
an underlayer on the first shield;
a first damping layer on the underlayer and consisting essentially of an element selected from the group consisting of Pt, Pd, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Th, Yb, and Lu;
a first ferromagnetic free layer on the first damping layer and having an in-plane magnetic moment in the absence of an applied magnetic field;
an electrically conducting nonmagnetic spacer layer on the first ferromagnetic layer;
a second ferromagnetic free layer on the spacer layer and having an in-plane magnetic moment nonparallel to the first free layer's magnetic moment in the absence of an applied magnetic field, said first and second free layer magnetic moments being free to rotate in opposite directions in the presence of a magnetic field from magnetically recorded data on the medium;
a second damping layer on the second free layer and consisting essentially of an element selected from the group consisting of Pt, Pd, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Th, Yb, and Lu;
a capping layer on the second damping layer;
a second shield of magnetically permeable material on the capping layer;
and
a hard magnetic biasing layer for biasing the first and second free layers' magnetic moments to be nonparallel in the absence of an applied magnetic field.

8 more elements

Dependencies are inferred from the claim text.

Scissoring-type current-perpendicular-to-the-plane giant magnetoresistance (cpp-gmr) sensors with damped free layer structures

Life of this patent

Scissoring-type current-perpendicular-to-the-plane giant magnetoresistance (cpp-gmr) sensors with damped free layer structures

Life of this patent

Abstract

Claims15