Non-Collinear Magnetic Coupling Layer Design

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Solution Overview

Problem

Current magnetic coupling layers, such as those with PtMn and RuFe, have limitations including weak coupling strength, limited ability to sense strong external magnetic fields, and instability upon annealing, which restrict their application in magnetic sensors and memory devices.

Innovation Solution

A magnetic device with non-collinearly coupled magnetic layers using a coupling layer comprising non-magnetic and magnetic elements, such as Ag, Cr, Ru, and Ni/Co/Fe, with specific atomic ratios and thicknesses to achieve strong coupling and stability across various angles and annealing temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If PtMn coupling layers with thickness less than 10 nm are used to achieve weak coupling strength, then the device can be made smaller, but the ability to sense strong external magnetic fields deteriorates

Engineering Contradiction:

Improvecoupling layer thicknessVSAvoidsensing capability for strong external magnetic fields

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent changes the compositional parameters of the coupling layer by introducing a gradient structure where the Pt concentration varies through the thickness of the layer. This gradient composition allows optimization of both thickness and coupling strength, enabling the device to sense stronger external magnetic fields while maintaining compact dimensions.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs composite coupling layer structures combining Pt with other magnetic elements (such as Co, Fe, or Ni) in specific ratios. This composite approach creates intermediate coupling strength that exceeds both PtMn and RuFe configurations, thereby enhancing the ability to detect strong external magnetic fields while keeping the layer thickness manageable.

Inventive Principle:

Principle #40Composite materials

2Volume of moving object

If PtMn coupling layers are used to achieve non-collinear coupling, then the device can operate at smaller dimensions, but stability upon annealing deteriorates

Engineering Contradiction:

Improvecoupling layer thicknessVSAvoidcoupling stability after annealing

Core Design Contradiction:

Volume of moving objectVSStability of the object's composition

Solution Approach 1:

The patent modifies the compositional parameters by creating a gradient in Pt concentration across the coupling layer thickness. This gradient structure provides thermal stability during annealing processes while maintaining the non-collinear coupling configuration, thus preserving both compact size and compositional stability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent applies different Pt concentrations at different positions within the coupling layer. The gradient composition creates local variations that stabilize the non-collinear coupling configuration during annealing, preventing degradation while maintaining overall compact device dimensions.

Inventive Principle:

Principle #3Local quality

3Reliability

If RuFe coupling layers are used to achieve stronger coupling than PtMn, then the sensing capability improves, but manufacturing complexity increases

Engineering Contradiction:

Improvecoupling strengthVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent simplifies manufacturing by using a gradient Pt concentration approach within a single coupling layer system, avoiding the need for complex multi-layer RuFe structures. This parameter optimization achieves strong coupling comparable to RuFe but with simpler fabrication processes.

Inventive Principle:

Principle #35Parameter changes

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 enables magnetic devices to sense stronger external magnetic fields and maintain non-collinear coupling stability after annealing, enhancing their performance in magnetic sensors and memory applications.

Implementation Method 1

a coupling layer for coupling magnetization directions of two or more spaced apart magnetic layers

Methodology Applied

Scientific EffectExchange interaction:

Implementation Method 2

for magnetoresistive sensor applications, such as those employing tunnel-magnetoresistance (TMR) or giant-magnetoresistance (GMR)

Methodology Applied

Scientific EffectTunnel magnetoresistance (TMR):

Implementation Method 3

for magnetoresistive sensor applications, such as those employing tunnel-magnetoresistance (TMR) or giant-magnetoresistance (GMR)

Methodology Applied

Scientific EffectGiant magnetoresistance (GMR):

Data Source

PatentUS10446208B2Applications of non-collinearly coupled magnetic layers

Publication Date: 2019.10.15 SIMON FRASER UNIVERSITY

AI summary

A magnetic device comprising having a first magnetic layer having a first magnetization direction, a second magnetic layer having a second magnetization direction, a first coupling layer interposed between the first and second magnetic layers, a third magnetic layer having a third magnetization direction, a first magnetoresistive layer interposed between the third magnetic layer and the second magnetic layer, and a circuit connected to one or more of the layers of the magnetic device by at least a pair of leads. The circuit is configured to determine a change in resistance between the pair of leads. The change in resistance is based at least in part on a change in an angular relationship between the third magnetization direction and the second magnetization direction caused by an external magnetic field or a current passing through at least a portion of the device.