スピン依存型トンネル装置の磁気安定性について
1IBM Research Division, Almaden Research Center, 650 Harry Road, K11/D2, San Jose, CA 95120-6099, USA.
Science (New York, N.Y.)
|August 7, 1998
まとめ
メモリデバイスで使用される鉄磁気トンネル接続は,繰り返し磁気スイッチングを繰り返すため,データを失う可能性があります. デマグネチゼーションはドメイン壁の動きによって起こりますが,一貫した回転によって防止され,データの安定性を確保します.
科学分野:
- スピントロニクス (Spintronics) は,スピントロニクス (Spintronics) を開発したものです.
- マテリアルサイエンス 材料科学
- 凝縮物質物理学 凝縮物質物理学
背景:
- 鉄磁性金属層のトンネリング抵抗は,磁化方向に依存する.
- メモリデバイスは,磁気的に柔らかい層と硬い層または交換バイアス層の独立した切り替えを使用します.
研究 の 目的:
- フィールドサイクリング中の鉄磁気トンネル交差点における脱磁メカニズムを調査する.
- 磁気トンネル交差点における記憶の安定性に影響する要因を決定する.
主な方法:
- 交換バイアスと磁気硬層の磁気トンネル交差点の比較分析.
- 磁気化の逆転を誘導するフィールドサイクリング. 柔らかい層.
- 磁気化の崩壊を監視し,逆転メカニズムを特定する.
主要な成果:
- 交換バイアスの構造は,10^7サイクルまで安定した磁化を示した.
- 磁気的に硬い構造は,磁場サイクルによる磁気化の対数分解を示した.
- 消磁化は,硬層の厚さと柔らかい層の組成に敏感でした.
- マグネチゼーションの逆転がコヒーレント・ローテーションで起きたとき,衰退は観察されなかった.
結論:
- フィールドサイクリング中の鉄磁気トンネル交差点における消磁化は,ドメイン壁の形成と柔らかい層の動きに起因する.
- マグネティゼーションの一貫した回転は,デマグネティゼーションを防止し,メモリの安定性を確保します.
- これらのメカニズムを理解することは,堅牢な磁気メモリデバイスの設計に不可欠です.
さらに関連する動画
06:27Fabrication of Magnetic Nanostructures on Silicon Nitride Membranes for Magnetic Vortex Studies Using Transmission Microscopy Techniques
Published on: July 2, 2018
07:42Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains
Published on: July 20, 2022
関連する概念動画
01:03Atomic Nuclei: Nuclear Spin State Overview
NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the absence of a magnetic field, the nuclear magnetic moments are randomly oriented, and the spin states are degenerate. When an external magnetic field is applied, the spin states have only 2 + 1 orientations available to them. A proton with = ½ has two available orientations. Similarly, for a quadrupolar nucleus with a nuclear spin value of one, the...
01:14Atomic Nuclei: Nuclear Spin State Population Distribution
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.
01:23Atomic Nuclei: Nuclear Relaxation Processes
In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin to precess and orient themselves along (lower energy) or against (higher energy) the direction of the field. At equilibrium, a slight excess population of spins exists in the lower energy state. Because the direction of the magnetic field is fixed as the z-axis, the precessing magnetic moments are randomly oriented around the z-axis. This...
01:28Magnetic Fields
A moving charge or a current creates a magnetic field in the surrounding space, in addition to its electric field. The magnetic field exerts a force on any other moving charge or current that is present in the field. Like an electric field, the magnetic field is also a vector field. At any position, the direction of the magnetic field is defined as the direction in which the north pole of a compass needle points.
A magnetic field is defined by the force that a charged particle experiences...
A magnetic field is defined by the force that a charged particle experiences...
01:26Diamagnetism
Materials consisting of paired electrons have zero net magnetic moments. However, when these materials are placed under an external magnetic field, the moments opposite to the field are induced. Such materials are called diamagnets. Diamagnetism is the response of the diamagnets when placed in an external magnetic field.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets.
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets.
01:30Paramagnetism
Paramagnets are materials with unpaired electrons that possess a finite magnetic moment. In the absence of a magnetic field, these moments are randomly oriented, and thus the net moment is zero. Under an external field, a torque acting on the moments tends to align them along the field's direction. However, the random thermal motion of electrons produces a torque opposite to the external field and tries to disorient the moments. These two competing effects align only a few moments along the...