Domain Wall Movement Layer With MgO Barrier for Write-Heat Stability

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Solution Overview

Problem

Domain wall movement elements experience reduced stability and reliability due to heat generation during write operations, which affects the integrity of stored data.

Innovation Solution

Incorporating a nonmagnetic layer with a specific structure, including regions of varying Mg and nonmagnetic element concentrations, to enhance heat dissipation and improve thermal conductivity, thereby maintaining magnetization stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a long domain wall movement layer is used to enable domain wall movement, then data can be recorded in multi-level or analog manner, but heat is generated during write operations which reduces magnetization stability and data reliability

Engineering Contradiction:

Improvedata recording capabilityVSAvoiddata reliability

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

A nonmagnetic layer is introduced as an intermediary between the reference layer and the domain wall movement layer. This nonmagnetic layer serves as a thermal management component that facilitates heat dissipation from the domain wall movement layer during write operations, thereby maintaining magnetization stability and data reliability while preserving the long domain wall movement layer's data recording capability

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The composition of the nonmagnetic layer is optimized by controlling the concentration of nonmagnetic elements (such as Ta, W, or Mo) to be 1-10 atom%. This parameter change in composition enables the nonmagnetic layer to achieve optimal thermal conductivity for effective heat dissipation, resolving the contradiction between maintaining data recording functionality and ensuring data reliability

Inventive Principle:

Principle #35Parameter changes

2Productivity

If write current is applied to the domain wall movement layer to move domain wall, then data can be written, but heat is generated which reduces the stability of magnetization

Engineering Contradiction:

Improvewrite operation capabilityVSAvoidmagnetization stability

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The nonmagnetic layer acts as a thermal intermediary that conducts heat away from the domain wall movement layer during write operations. This allows write current to be applied for domain wall movement while the nonmagnetic layer simultaneously manages the thermal load, preventing magnetization instability

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The nonmagnetic layer is constructed as a composite material containing MgO or Mg-containing oxide combined with nonmagnetic elements (Ta, W, Mo) at specific concentrations. This composite structure provides both the necessary thermal conductivity for heat dissipation and the structural properties needed to maintain magnetization stability during write operations

Inventive Principle:

Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution provides high heat exhaust efficiency, ensuring data reliability and reducing the likelihood of element failure by effectively dissipating heat generated during operations.

Implementation Method 1

The nonmagnetic layer includes a first region and a second region. The first region includes an oxide of Mg or an oxide containing Mg and a nonmagnetic element other than Mg. The second region includes an oxide containing Mg and the nonmagnetic element. A concentration of the nonmagnetic element in the second region is higher than a concentration of the nonmagnetic element in the first region by 0.1 atom % or more.

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS12477953B2Domain wall movement element, magnetoresistive element, and magnetic array

Publication Date: 2025.11.18 TDK CORP

AI summary

A domain wall movement element includes a reference layer, nonmagnetic layer, domain wall movement layer, and first and second magnetization fixed layers. The first layer is connected to the domain wall movement layer. The second layer is connected to the domain wall movement layer at a position different from the first in a first direction. The nonmagnetic layer is interposed between the reference layer and domain wall movement layer in a stacking direction. The nonmagnetic layer includes first and second regions. The first region includes an oxide of Mg or an oxide containing Mg and a nonmagnetic element other than Mg. The second region includes an oxide containing Mg and a nonmagnetic element. A concentration of the nonmagnetic element in the second region is higher than that of the first region by 0.1 atom % or more. The second region is discontinuous in a plane orthogonal to the stacking direction.