Configuration for minimizing the Neel interaction between two ferromagnetic layers on both sides of a non-ferromagnetic separating layer

• US 6,646,530 B2
• Filed: 10/31/2002
• Issued: 11/11/2003
• Est. Priority Date: 10/31/2001
• Status: Expired due to Term

• Current Assignee: Polaris Innovations Limited (Wi-LAN Inc.)
• Original Assignee: Infineon Technologies AG
• Inventors: Rührig, Manfred
• Primary Examiner(s): Barrera, Ramon M.
• Application Number:
  US10/284,775
• Publication Number:
  US 20030117247A1
• Time in Patent Office: 376 Days
• Field of Search: 335/306, 365/157, 365/158, 365/171, 365/173
• US Class Current: 335/306
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G01R 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00

Abstract

A configuration for minimizing and compensating for the Néel interaction between a first ferromagnetic layer and a second ferromagnetic layer on both sides of a nonmagnetic separating layer has an artificial anti-ferromagnetic layer system. The two ferromagnetic layers each being sublayers of an artificial anti-ferromagnetic layer system contribute to the minimization of the Néel interaction.

Claims

1. A configuration for minimizing a Né

el interaction, comprising;

a first asymmetrical artificial anti-ferromagnetic layer system having a first ferromagnetic sublayer, a second ferromagnetic sublayer, and a first spacer layer disposed between said first and second ferromagnetic sublayers;

a separating layer, said first ferromagnetic sublayer being oriented toward said separating layer and having a smaller layer thickness than said second ferromagnetic sublayer of said first asymmetrical artificial anti-ferromagnetic layer system; and

a second asymmetrical artificial anti-ferromagnetic layer system having a first ferromagnetic sublayer oriented toward said separating layer, a second ferromagnetic sublayer, and a second spacer layer disposed between said first and second ferromagnetic sublayers of said second asymmetrical artificial anti-ferrromagnetic layer system, said first ferromagnetic sublayer of said second asymmetrical artificial anti-ferromagnetic layer system having a smaller layer thickness than said second ferromagnetic sublayer of said second asymmetrical artificial anti-ferromagnetic layer system, and resulting total magnetizations of said first and second asymmetrical artificial anti-ferromagnetic layer systems being accumulated vectorially in a manner that compensates for the Né

el interaction between said first ferromagnetic sublayer of said first asymmetrical artificial anti-ferromagnetic layer system and said first ferromagnetic sublayer of said second asymmetrical artificial anti-ferromagnetic layer system each being oriented toward said separating layer.

2. The configuration according to claim 1, wherein said first symmetrical artificial anti-ferromagnetic layer system is a reference layer system and said second asymmetrical artificial anti-ferromagnetic layer system is a memory layer system of a magneto-resistive memory cell.

3. The configuration according to claim 2, wherein said magneto-resistive memory cell is based on a tunnel effect and said separating layer is composed of a dielectric material and functioning as a tunnel barrier.

4. The configuration according to claim 3, further comprising at least one exchange bias layer disposed at a surface of said reference layer system lying remote from said tunnel barrier and a magnetization of said exchange bias layer is fixedly coupled to a magnetization of said reference layer system.

5. The configuration according to claim 4, wherein said exchange bias layer extends beyond dimensions of said reference layer system in a plane parallel to said tunnel barrier.