# US 9,520,175 B2 · Magnetization controlling element using magnetoelectric effect

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- Number: US 9,520,175 B2
- Document ID: US9520175B2
- Status: Granted
- Kind: B2
- Application number: 14/532,533
- Filed: 2014-11-04
- Published: 2015-05-07
- Granted: 2016-12-13
- Earliest claimed: 2013-11-05
- Assignees: TDK Corporation
- Applicants: TDK Corporation
- Inventors: Tatsuo Shibata; Masashi Sahashi
- Web page: https://patentgrep.com/patent/US9520175B2

## CPC

- G11C 11/1677: {Verifying circuits or methods}
- G11B 5/02: Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
- G11C 11/15: using multiple magnetic layers (G11C11/155 takes precedence)
- G11C 11/161: {details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell}
- G11C 11/1675: {Writing or programming circuits or methods}
- H01F 10/3218: {Exchange coupling of magnetic films via an antiferromagnetic interface (H01F10/3268 takes precedence)}
- H01F 10/3286: {Spin-exchange coupled multilayers having at least one layer with perpendicular magnetic anisotropy}
- G11B 5/012: Recording on, or reproducing or erasing from, magnetic disks (G11B17/00, G11B19/00 take precedence)
- H01F 10/3272: {by use of anti-parallel coupled [APC] ferromagnetic layers, e.g. artificial ferrimagnets [AFI], artificial [AAF] or synthetic [SAF] anti-ferromagnets}
- G11C: STATIC STORES (semiconductor memory devices H10B)
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES

## Abstract

A magnetization controlling element includes a ferromagnetic material layer, an exchange coupling adjustment layer, an antiferromagnetic material layer, an electrode layer, a magnetic field applying mechanism which applies a magnetic field to the antiferromagnetic material layer, and an electric field applying mechanism which applies an electric field to the antiferromagnetic material layer. The antiferromagnetic material layer contains an antiferromagnetic material or ferrimagnetic material having a magnetoelectric effect, the ferromagnetic material layer includes a perpendicular magnetization film having a magnetization component perpendicular to the film surface, the ferromagnetic material layer includes a ferromagnetic material layer that is magnetically connected, through exchange coupling, to the antiferromagnetic material layer. The exchange coupling adjustment layer has a function of adjusting exchange coupling between the ferromagnetic material layer and the antiferromagnetic material layer.

## Claims

### Claim 1

A magnetization controlling element comprising:
a ferromagnetic material layer;
an exchange coupling adjustment layer;
an antiferromagnetic material layer;
an electrode layer;
a magnetic field applying mechanism; and
an electric field applying mechanism,
wherein the ferromagnetic material layer, the exchange coupling adjustment layer, the antiferromagnetic material layer, and the electrode layer are disposed in that order from the ferromagnetic material layer side,
the magnetic field applying mechanism applies a magnetic field to the antiferromagnetic material layer,
the electric field applying mechanism applies an electric field to the antiferromagnetic material layer,
the antiferromagnetic material layer is an insulator and contains an antiferromagnetic material or ferrimagnetic material having a magnetoelectric effect,
the ferromagnetic material layer includes a ferromagnetic material layer that is magnetically connected, through exchange coupling, to the antiferromagnetic material layer,
the exchange coupling adjustment layer has a function of adjusting exchange coupling between the ferromagnetic material layer and the antiferromagnetic material layer, and
the exchange coupling adjustment layer has a thickness of from 0.25 nm to 1.0 nm and contains at least one element selected from the group consisting of transition metal elements excluding ferromagnetic metals, light metal elements, and semiconductor elements, whose atomic number is 45 or lower.

### Claim 2 (depends on 1)

The magnetization controlling element according to claim 1, wherein the exchange coupling adjustment layer contains a transition metal element whose atomic number is 45 or lower excluding ferromagnetic metals, and the transition metal element includes at least one element of Ti, V, Cr, Cu, Zr, Nb, Mo, Ru, and Rh.

### Claim 3 (depends on 1)

The magnetization controlling element according to claim 1, wherein the exchange coupling adjustment layer contains a light metal element whose atomic number is 45 or lower, and the light metal element includes at least one element of Mg and Al.

### Claim 4 (depends on 1)

The magnetization controlling element according to claim 1, wherein the exchange coupling adjustment layer contains a semiconductor element whose atomic number is 45 or lower, and the semiconductor element includes at least one element of Si and Ge.

### Claim 5 (depends on 1)

The magnetization controlling element according to claim 1, wherein the ferromagnetic material layer includes a perpendicular magnetization film having a magnetization component perpendicular to the film surface.