Magnetic Recording Medium Crystal Alignment for Long-Term Stability

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Solution Overview

Problem

Magnetic recording media containing ε-iron oxide powder tend to experience deterioration in running stability after long-term storage, leading to decreased reproducing output and off-track issues.

Innovation Solution

A magnetic recording medium with a magnetic layer containing ε-iron oxide powder, where the intensity ratio of diffraction intensities after pressing at 70 atm is controlled between 1.0 and 6.5, enhancing the alignment of crystal planes with lubricants to improve sliding stability and reduce debris formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ε-iron oxide powder is used as ferromagnetic powder in the magnetic layer, then the magnetic recording medium achieves good initial running stability, but running stability deteriorates after long-term storage

Engineering Contradiction:
Improverunning stabilityVSAvoidlong-term storage durability
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The invention controls the intensity ratio (Int1/Int2) of specific diffraction peaks as a critical parameter to maintain running stability after long-term storage. By optimizing this XRD intensity ratio parameter within a specific range, the magnetic layer's crystal structure is controlled to prevent deterioration during archiving, directly resolving the contradiction between initial stability and long-term durability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The magnetic layer uses ε-iron oxide powder as the ferromagnetic component, which provides both good initial running stability and archival suitability when properly controlled. This composite material approach combines the advantages of ε-iron oxide while mitigating its long-term stability issues through precise structural control

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If the magnetic layer is pressed at high pressure to improve alignment, then crystal plane alignment improves, but the intensity ratio may fall outside the optimal range

Engineering Contradiction:
Improvecrystal plane alignmentVSAvoidrunning stability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The invention establishes a specific intensity ratio range (Int1/Int2) as the optimal parameter window that balances crystal alignment with running stability. By controlling the pressing conditions to achieve this specific parameter range, both alignment quality and operational reliability are optimized simultaneously

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The XRD intensity ratio serves as a feedback parameter to evaluate and control the pressing process. By measuring the intensity ratio after pressing and comparing it against the target range, the manufacturing process can be adjusted to achieve optimal crystal alignment while ensuring running stability

Inventive Principle:
Principle #23Feedback

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 controlled intensity ratio maintains running stability after long-term storage by minimizing debris occurrence and maintaining lubricant functionality, ensuring consistent data retrieval performance.

Implementation Method 1

an intensity ratio (Int1/Int2) of diffraction intensities obtained by an X-ray diffraction analysis of the magnetic layer

Methodology Applied
Scientific EffectX-ray diffraction: X-Ray

Data Source

PatentUS12159657B2Magnetic recording medium having characterized magnetic layer, magnetic tape cartridge, and magnetic recording and reproducing device
Publication Date: 2024.12.03 FUJIFILM CORP

AI summary

Provided are a magnetic recording medium including a non-magnetic support, and a magnetic layer including a ferromagnetic powder. The ferromagnetic powder is an ε-iron oxide powder, and an intensity ratio (Int1/Int2) of diffraction intensities obtained by an X-ray diffraction analysis of the magnetic layer using an In-Plane method after the magnetic layer is pressed at a pressure of 70 atm is 1.0 or more and 6.5 or less, a magnetic tape cartridge and a magnetic recording and reproducing device each including the magnetic recording medium.