Magnetic switching with expanded hard-axis magnetization volume at magnetoresistive bit ends
A magnetoresistive apparatus and method of operation with improved switching characteristics is provided. Switching of a magnetic direction of a magnetic layer of a magnetoresistive bit is promoted by parallel rotation of local magnetic direction of ends of the bit toward alignment with a hard-axis of the bit. Thus, an embodiment provides for expanded hard-axis magnetic volume of the bit ends to support hard-axis magnetization through bit shape alteration or doping, for example. A method provides for applying a hard-axis magnetic field to the bit ends for initiating switching and applying an easy-axis magnetic field for completing switching.
1. A method of switching a magnetization of a magnetic layer comprising:
applying a first hard-axis magnetic field to a first end of the layer, wherein the first end has an expanded hard-axis magnetic volume;
applying a second hard-axis magnetic field to a second end of the layer, wherein the second end has an expanded hard-axis magnetic volume; and
applying an easy-axis magnetic field to a body of the bit, wherein the body is configured to support an easy-axis magnetization.
2. The method for switching of claim 1 , further comprising:
in response to applying the first and second magnetic fields, forcing a magnetic state of the first end to become parallel with a magnetic state of the second end.
3. The method for switching of claim 2 , further comprising:
removing the applied magnetic fields; and
returning the magnetic states of the ends to an anti-parallel state.
4. The method of claim 1 , wherein applying both the first and second magnetic fields comprises passing a current through a conducting line arranged near the bit.
5. The method of claim 1 , wherein the easy-axis is substantially perpendicular to the hard-axis.
6. A method for switching a magnetization of a magnetic layer comprising:
applying a first magnetic field to an end of the layer for rotating elemental magnetization directions within the layer toward a hard-axis direction, wherein the end has an expanded hard-axis magnetic volume;
applying a second magnetic field to a body of the bit, wherein the body is configured to support an easy-axis magnetization.
7. The method for switching of claim 6 , further comprising applying a bias current during a read sequence.
8. The method for switching of claim 6 , wherein the first magnetic field is substantially a hard-axis magnetic field.