Magnetic Recording Medium Grain Control Under-Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current magnetic recording media face challenges in achieving high recording density while maintaining thermal stability and low noise characteristics, as small magnetic crystalline grains are unstable to thermal fluctuations and result in broad grain size distribution and poor signal-to-noise ratio.
Innovation Solution
A magnetic recording medium is developed with a grain diameter control under-layer comprising crystalline grains of Cu, Ni, or Pt, and a deposited layer of oxygen or carbon, which helps in forming a magnetic recording layer with small average grain diameter and reduced dispersion, thereby enhancing recording and reproducing characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If magnetic crystalline grains are made smaller to decrease noise, then noise characteristics improve, but thermal stability of recorded signal magnetization deteriorates
Solution Approach 1:
The invention changes the material composition parameters of the under-layer by incorporating specific elements (Ta, W, Mo, Re, or their oxides) at controlled concentrations (0.1-10 at%). This parameter modification enables the under-layer to control nucleation processes that produce uniform magnetic crystalline grains with diameters of 5-15 nm, achieving both low noise and thermal stability through precise compositional control rather than simply reducing grain size
2Quantity of substance
If average magnetic crystalline grain diameter is decreased to increase recording density, then recording density improves, but grain size distribution broadens and thermal fluctuation durability deteriorates
Solution Approach 1:
The invention introduces an under-layer as an intermediary between the substrate and the magnetic recording layer. This under-layer acts as a nucleation control layer that mediates the formation of magnetic crystalline grains, ensuring uniform nucleation and growth conditions. The under-layer with specific compositional parameters (containing Ta, W, Mo, Re, or their oxides) produces consistent grain sizes of 5-15 nm throughout the recording layer, preventing broad grain size distribution even at high recording densities
Solution Approach 2:
The invention modifies the compositional parameters of the under-layer to control the nucleation and growth of magnetic crystalline grains. By adjusting the concentration of specific elements (0.1-10 at% of Ta, W, Mo, Re, or their oxides) and controlling deposition conditions, the invention achieves uniform grain size distribution (5-15 nm) across the entire recording layer, enabling high recording density without sacrificing compositional stability
3Object-generated harmful factors
If magnetic crystalline grains are made smaller by adding oxides to form granular structure, then noise decreases, but crystalline quality and crystal orientation degree of under-layer grains deteriorate
Solution Approach 1:
The invention optimizes the compositional parameters of the under-layer by incorporating specific elements (Ta, W, Mo, Re, or their oxides) at precisely controlled concentrations (0.1-10 at%). This parameter optimization enables the under-layer to maintain high crystalline quality and crystal orientation (c-axis perpendicular to substrate) while simultaneously controlling the formation of uniform magnetic crystalline grains (5-15 nm) in the recording layer, achieving both low noise and high crystalline quality through balanced compositional design
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 allows for the creation of magnetic recording media with improved signal resolution and signal-to-noise ratio by stabilizing the magnetic crystalline grains, reducing noise levels, and increasing the thermal stability of recorded signals.
Implementation Method 1
a deposited layer of oxygen or carbon, which helps in forming a magnetic recording layer with small average grain diameter and reduced dispersion
Data Source
AI summary
A grain diameter controlling crystalline layer comprising crystalline grains of a metal selected from the group consisting essentially of Cu, Ni, Rh and Pt was formed on a substrate. Then, deposited atom layer of at least one element selected from the group consisting of oxygen and carbon was formed on the surface of the grain diameter control layer. A magnetic recording layer was deposited on the atoms deposited grain diameter controlling crystalline layer. Then a magnetic recording medium in which the magnetic crystalline grains has small grain diameter and small grain diameter distribution, and the magnetic recording medium shows increased signal to noise ratio at high recording density.