Magnetoresistance effect element and magnetic memory device

Patent metadata

Field	Value
Publication number	US-10410703-B2
Application number	US-201715810896-A
Country	US
Kind code	B2
Filing date	Nov 13, 2017
Priority date	May 14, 2015
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

A magnetoresistance effect element includes a recording layer containing a ferromagnetic body, and including a first fixed and second magnetization regions having magnetization components fixed substantially in a direction antiparallel to the in-plane direction to each other, and a free magnetization region disposed between the first and second fixed magnetization regions and having a magnetization component invertible in the in-plane direction, a domain wall disposed between the first fixed magnetization region and the free magnetization region, and being movable within the free magnetization region, and a magnetic nanowire having a width of 40 nm or less. The thickness of the recording layer is 40 nm or less and at least half but no more than twofold the width of the magnetic nanowire. The element further includes a barrier layer disposed on the recording layer, and a reference layer disposed on the barrier layer and containing a ferromagnetic body.

First claim

What is claimed is:

1. A magnetoresistance effect element, comprising:
a recording layer containing a ferromagnetic body, the recording layer including
a first fixed magnetization region having a magnetization component fixed substantially in an in-plane direction,
a second fixed magnetization region having a magnetization component fixed substantially in a direction antiparallel to the in-plane direction of the magnetization component of the first fixed magnetization region,
a free magnetization region disposed between the first fixed magnetization region and the second fixed magnetization region, the free magnetization region having a magnetization component that is invertible in the in-plane direction,
a domain wall disposed between the first fixed magnetization region and the free magnetization region, and being movable within the free magnetization region, and
a magnetic nanowire having a width of 40 nm or less, the recording layer having a thickness of 40 nm or less, the thickness of the recording layer being at least half but no more than twofold the width of the magnetic nanowire;

a barrier layer disposed on the recording layer; and
a reference layer disposed on the barrier layer and containing a ferromagnetic body.

2. The magnetoresistance effect element according to claim 1 , wherein
the recording layer contains Ni and Fe,
the width of the magnetic nanowire in the recording layer is 30 nm or less, and
the thickness of the recording layer is 30 nm or less and at least two-thirds but no more than one and one half times the width of the magnetic nanowire.

3. The magnetoresistance effect element according to claim 1 , wherein
the recording layer has a first length in a first direction and a second length in a second direction that is perpendicular to the first direction provided that the first length is greater than the second length, and
the magnetization component of the free magnetization region is inverted by applying an electrical current through the recording layer in the first direction.

4. The magnetoresistance effect element according to claim 1 , wherein the domain wall is formed between the first fixed magnetization region and the free magnetization region or between the second fixed magnetization region and the free magnetization region, depending on direction of the magnetization component of the free magnetization region.

5. The magnetoresistance effect element according to claim 1 , further comprising a magnetization fixing layer that fixes at least one of (a) direction of the magnetization component of the first fixed magnetization region and (b) direction of the magnetization component of the second fixed magnetization region.

6. The magnetoresistance effect element according to claim 1 , wherein the recording layer includes a pinning site provided either between the first fixed magnetization region and the free magnetization region or between the second fixed magnetization region and the free magnetization region.

7. A magnetic memory device, comprising:
the magnetoresistance effect element according to claim 1 ;
a writing unit configured to write data into the magnetoresistance effect element by applying a writing current between the first fixed magnetization region and the second fixed magnetization region through the free magnetization region in the recording layer, to thereby move the domain wall; and
a reading unit configured to read out data from the magnetoresistance effect element by applying a current through the barrier layer in a direction parallel to a thickness direction of the magnetoresistance element that is effective to obtain a tunnel resistance.

8. The magnetoresistance effect element according to claim 1 , wherein the free magnetization region in the recording layer has a thickness of 40 nm or less, the thickness of the recording layer being at least half but no more than twofold the width of the magnetic nanowire.

Assignees

• Univ Tohoku

Inventors

• Fukami Shunsuke
• Iwabuchi Toru
• Ohno Hideo
• Endoh Tetsuo

Classifications

• H01F1/0072

  one dimensional, i.e. linear or dendritic nanostructures · CPC title

• G11C11/1675

  Writing or programming circuits or methods · CPC title

• H01F10/3254

  the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ] · CPC title

• G01R33/098

  comprising tunnel junctions, e.g. tunnel magnetoresistance sensors · CPC title

• G11C11/1659 Primary

  Cell access · CPC title