Magnetic Head Stacked Body for High Density Recording

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Solution Overview

Problem

Current magnetic recording devices face limitations in increasing recording density due to the inefficiency of the magnetic field orientation towards the recording medium, particularly at smaller recording gaps.

Innovation Solution

A magnetic head design incorporating a stacked body with specific magnetic and nonmagnetic layers, including Fe, Co, Ni, Cr, V, Mn, Ti, Sc, Cu, Ag, Au, Al, Ta, Pt, W, Mo, Ir, Ru, and Pd, which alters the electrical resistance characteristics when current is applied, enhancing the orientation and efficiency of the recording magnetic field.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a conventional magnetic head structure is used, then the device complexity is low, but the recording density cannot be increased due to inefficient magnetic field orientation

Engineering Contradiction:

Improverecording densityVSAvoidstacked body structure

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The magnetic head is divided into multiple functional layers including first and second magnetic layers, first and second nonmagnetic layers, and a stacked body with alternating magnetic and nonmagnetic layers. This segmentation allows each layer to perform specific functions for optimizing magnetic field orientation and increasing recording density.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The stacked body is constructed using composite materials with alternating magnetic layers (containing Co, Fe, Ni) and nonmagnetic layers (containing Ru, Rh, Ir, Pd, Pt), creating a composite structure that enhances magnetic field orientation efficiency and enables higher recording density.

Inventive Principle:

Principle #40Composite materials

2Manufacturing precision

If the recording gap is reduced to increase recording density, then the recording density increases, but the magnetic field orientation efficiency decreases

Engineering Contradiction:

Improverecording densityVSAvoidmagnetic field orientation efficiency

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The invention changes the structural parameters of the magnetic head by introducing a stacked body with specific layer thicknesses (first magnetic layer: 2-10nm, second magnetic layer: 2-5nm, first nonmagnetic layer: 1-5nm, second nonmagnetic layer: 1-5nm) and material compositions, which maintains magnetic field orientation efficiency even at reduced recording gaps for increased recording density.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If high-speed recording operations are implemented, then the productivity increases, but the bit error rate increases due to insufficient magnetization reversal speed

Engineering Contradiction:

Improverecording speedVSAvoidbit error rate

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The stacked body is designed with specific local material properties where the first magnetic layer contains Co, Fe, or Ni with specific thickness (2-10nm) to achieve fast magnetization reversal, while the second magnetic layer (2-5nm) and nonmagnetic layers provide local structural quality that maintains low bit error rate during high-speed recording operations.

Inventive Principle:

Principle #3Local quality

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 design allows for increased recording density and reduced recording gaps while improving magnetization reversal speed and bit error rate, enabling high-speed and high-frequency recording operations.

Implementation Method 1

Methodology Applied

Scientific EffectMagnetoresistance: Magnetoresistance

Data Source

PatentUS11626130B2Magnetic head with stacked body having specified compositions of magnetic and nonmagnetic layers thereof

Publication Date: 2023.04.11 KK TOSHIBA

AI summary

According to one embodiment, a magnetic head includes a first magnetic pole, a second magnetic pole, 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 first magnetic layer and the second magnetic pole, a second nonmagnetic layer provided between the second and first magnetic layers, and a third nonmagnetic layer provided between the third and second magnetic layers. The third magnetic layer includes first and second elements. The first and second magnetic layers do not include the second element. Or concentrations of the second element in the first and second magnetic layers are less than in the third magnetic layer.