Magnetic Recording Medium Cu Under-Layer Nitrogen Grain Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for achieving high recording density in magnetic recording media face challenges in stabilizing thermal fluctuations and reducing noise, as they result in broad grain size distributions and poor thermal durability due to small magnetic crystalline grain sizes.
Innovation Solution
A magnetic recording medium is developed with a Cu metal film under-layer and a deposited layer of nitrogen atoms, which controls the grain diameter and orientation of the magnetic recording-layer, allowing for smaller grain sizes with improved thermal stability and reduced noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the average magnetic crystalline grain diameter is decreased to reduce noise, then noise is reduced, but thermal stability deteriorates due to thermal fluctuation effects
Solution Approach 1:
The invention changes the parameter of grain size distribution from broad to narrow by controlling the under-layer structure. By using a Cu under-layer with specific grain size (50-200 nm) and adding nitrogen atoms (1×10^13 to 1×10^15 atoms/cm²), the magnetic crystalline grains achieve uniform size distribution, which simultaneously reduces noise and maintains thermal stability.
Solution Approach 2:
The invention introduces nitrogen atoms as an intermediary substance between the Cu under-layer and the magnetic recording layer. These nitrogen atoms mediate the grain growth process, controlling both the size and uniformity of magnetic crystalline grains, thereby resolving the contradiction between noise reduction and thermal stability.
2Productivity
If the magnetic crystalline grain size is made smaller to increase recording density, then recording density is improved, but thermal fluctuation durability deteriorates
Solution Approach 1:
The invention optimizes the parameter of grain size distribution to achieve narrow distribution with small average grain size. By controlling the under-layer Cu grain size and nitrogen atom concentration, the magnetic grains achieve uniform small size (reducing noise) while maintaining sufficient thermal stability for high recording density.
Solution Approach 2:
The invention applies local quality control by creating specific conditions at the under-layer interface. The Cu under-layer with controlled grain size and nitrogen atom concentration provides localized control over magnetic grain formation, enabling small uniform grains with good thermal stability.
3Manufacturing precision
If the under-layer crystalline grain diameter is decreased to control magnetic layer grains, then magnetic grain size is reduced, but crystalline quality and orientation degree are degraded
Solution Approach 1:
The invention changes the parameter of under-layer Cu grain size to an optimal range (50-200 nm) and adds nitrogen atoms to control magnetic grain size without degrading crystalline quality. This parameter optimization allows precise magnetic grain control while maintaining good crystalline structure and orientation.
Solution Approach 2:
Nitrogen atoms serve as an intermediary that mediates between the Cu under-layer structure and the magnetic recording layer. They enable control of magnetic grain size while preserving the crystalline quality and orientation degree of the under-layer.
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 approach enables the production of magnetic recording media with increased recording and reproducing characteristics, including a higher signal-to-noise ratio, by achieving smaller and more uniformly sized magnetic crystalline grains.
Implementation Method 1
a deposited layer of nitrogen atoms formed on the grain diameter control under-layer
Data Source
AI summary
A magnetic recording layer is formed on an under-layer comprising a Cu crystalline grain layer and a deposited nitrogen atom layer on the Cu crystalline grain layer surface. Then the magnetic recording layer comprising very small average grain diameter and sharp grain diameter distribution is obtained. The magnetic recording medium comprising the magnetic recording layer shows excellent signal to noise ratio at high density recording.