L10 Magnetic Recording Medium with Granular Grain Boundaries
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current magnetic recording media face challenges in achieving high signal-noise ratio (SNR) and recording volume, particularly in maintaining good electromagnetic transducing properties.
Innovation Solution
A magnetic recording medium is designed with a (001) oriented L10 magnetic layer having a granular structure with carbon at the grain boundaries in the first magnetic layer and oxide or nitride at the grain boundaries in the second magnetic layer, further incorporating elements like Mg, Ni, Zn, Ge, Pd, Sn, Ag, Re, Au, or Pb in the second layer to enhance grain separation and orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a high Ku magnetic material is used to achieve fine grain size and high surface density, then heat stability is improved, but electromagnetic transducing properties and SNR deteriorate
Solution Approach 1:
The patent applies local quality by creating distinct regions within the magnetic layer: magnetic grains with high Ku material for heat stability, and grain boundary portions with different composition (containing B, C, N, or O) that provide superior electromagnetic transducing properties. This spatial differentiation allows each region to optimize its local function while contributing to overall performance.
Solution Approach 2:
The patent employs composite materials by combining high Ku magnetic materials (such as L10 FePt, L10 CoPt, or L11 CoPt) with grain boundary materials containing boron, carbon, nitrogen, or oxygen. This composite structure achieves both fine grain size for high density and excellent electromagnetic transducing properties through the synergistic interaction of different materials in specific locations.
2Reliability
If crystal grains are separated by grain boundary phase to reduce exchange couplings, then medium SNR is improved, but recording volume deteriorates
Solution Approach 1:
The patent applies parameter changes by precisely controlling the composition parameters of the grain boundary portions, specifically incorporating elements like B, C, N, or O at controlled concentrations. This changes the magnetic and structural parameters of the grain boundaries to achieve optimal separation that reduces exchange couplings while preserving recording volume through efficient space utilization.
3Stability of the object's composition
If grain size is made fine to increase surface density, then heat stability is improved, but electromagnetic transducing properties deteriorate
Solution Approach 1:
The patent applies local quality by creating distinct regions within the magnetic layer: magnetic grains with high Ku material for heat stability, and grain boundary portions with different composition (containing B, C, N, or O) that provide superior electromagnetic transducing properties. This spatial differentiation allows each region to optimize its local function while contributing to overall performance.
Solution Approach 2:
The patent employs composite materials by combining high Ku magnetic materials (such as L10 FePt, L10 CoPt, or L11 CoPt) with grain boundary materials containing boron, carbon, nitrogen, or oxygen. This composite structure achieves both fine grain size for high density and excellent electromagnetic transducing properties through the synergistic interaction of different materials in specific locations.
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 promotes high SNR by improving the orientation and ordered degree of magnetic grains, reducing exchange couplings, and maintaining heat stability, thereby enhancing the recording medium's performance in magnetic memory devices.
Implementation Method 1
By forming the magnetic layer to have a granular structure in which crystal grains are separated by a grain boundary phase, exchange couplings between the magnetic grains can be reduced and high medium SNR (signal-noise ratio) can be actualized.
Implementation Method 2
Thermally-Assisted Magnetic Recording (TAMR) is suggested by which data is recorded on a magnetic recording medium while heating the magnetic recording medium by a magnetic head on which a laser light source is mounted. According to TAMR, as magnetic coercive force can be largely reduced by heating the magnetic recording medium
Implementation Method 3
a material whose magnetic crystalline anisotropy constant Ku is high (hereinafter, referred to as a 'high Ku magnetic material' as well) can be used for a magnetic layer of the magnetic recording medium. Thus, grain-size of magnetic materials can be made fine while retaining heat stability
Data Source
AI summary
A magnetic recording medium includes a substrate; a lower base layer formed on the substrate; and a (001) oriented L10 magnetic layer formed on the lower base layer and including a first magnetic layer formed on the lower base layer and having a granular structure of magnetic grains and a grain boundary portion, the grain boundary portion containing C, and a second magnetic layer formed on the first magnetic layer and having a granular structure of magnetic grains and a grain boundary portion, the grain boundary portion containing oxide or nitride, the second magnetic layer further containing one or more elements selected from a group consisting of Mg, Ni, Zn, Ge, Pd, Sn, Ag, Re, Au and Pb as an additive.