Magnetic Head Stacked Body Stabilizes Magnetization

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Solution Overview

Problem

Current magnetic recording devices face challenges in increasing recording density due to inefficient application of the recording magnetic field, particularly when the recording gap is small, and instability in magnetization of magnetic layers.

Innovation Solution

A magnetic head with a stacked body configuration including specific magnetic and nonmagnetic layers, where the second magnetic layer has distinct magnetic regions with different spin polarizations, and a current orientation from the first magnetic layer toward the third magnetic layer, stabilizes magnetization and enhances the recording magnetic field application.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the recording gap is reduced to increase recording density, then the recording density is improved, but the application efficiency of the recording magnetic field deteriorates

Engineering Contradiction:

Improverecording densityVSAvoidapplication efficiency of recording magnetic field

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent introduces a stacked body with multiple magnetic layers (first magnetic layer, second magnetic layer, third magnetic layer) having different magnetization directions. The second magnetic layer has magnetization in the plane of the recording gap while the first and third magnetic layers have magnetization perpendicular to the recording gap. This local differentiation of magnetic properties allows the structure to simultaneously achieve high recording density through reduced gap and maintain effective magnetic field application through the specific magnetization configuration of different layers.

Inventive Principle:

Principle #3Local quality

2Quantity of substance

If the recording gap is reduced to increase recording density, then the recording density is improved, but the magnetization stability of magnetic layers deteriorates

Engineering Contradiction:

Improverecording densityVSAvoidmagnetization stability

Core Design Contradiction:

Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent configures the second magnetic layer with magnetization in the plane of the recording gap, while the first and third magnetic layers have magnetization perpendicular to the recording gap. This localized differentiation creates a stable magnetization configuration that prevents unwanted magnetization changes in the recording gap region, thereby maintaining magnetization stability even at reduced gap dimensions that would otherwise compromise stability.

Inventive Principle:

Principle #3Local quality

3Ease of manufacture

If the magnetic head structure is simplified to improve manufacturing ease, then the manufacturing ease is improved, but the recording density capability deteriorates

Engineering Contradiction:

Improvemanufacturing easeVSAvoidrecording density capability

Core Design Contradiction:

Ease of manufactureVSQuantity of substance

Solution Approach 1:

The patent employs a stacked body structure where multiple magnetic layers are nested within each other in a vertical arrangement. The first, second, and third magnetic layers are stacked with their magnetization directions oriented differently relative to the recording gap. This nested configuration achieves high recording density capability through the multi-layer structure while maintaining a compact form factor that is compatible with conventional manufacturing processes.

Inventive Principle:

Principle #7Nested doll (Nesting)

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

This configuration effectively increases recording density by stabilizing magnetization and efficiently applying the recording magnetic field, even at reduced recording gaps, improving recording performance.

Implementation Method 1

Methodology Applied

Scientific EffectSpin-transfer torque:

Data Source

PatentUS11348606B2Magnetic head for high density magnetic recording device

Publication Date: 2022.05.31 KK TOSHIBA

AI summary

According to one embodiment, a magnetic head includes first and second magnetic poles, and a stacked body provided between the first and second magnetic poles. The stacked body includes a first magnetic layer, a second magnetic layer provided between the first magnetic pole and the first magnetic layer, a third magnetic layer provided between the first magnetic pole and the second magnetic layer, a first nonmagnetic layer provided between the second and first magnetic layers, a second nonmagnetic layer provided between the third and second magnetic layers, and a third nonmagnetic layer provided between the first magnetic pole and the third magnetic layer. The second magnetic layer includes first and second magnetic regions. The second magnetic region is between the second nonmagnetic layer and the first magnetic region. The first magnetic region includes a first element. The second magnetic region includes the first element, and a second element.