Magnetic Storage Technology

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Magnetic Storage Technology
Mladen Barbic
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Outline

• Overview of a Hard Drive system
• Historical Progress
• Basics of magnetic non-volatile storage
• Inductive write head
• Magneto-resistive read elements
• Magnetic recording media
• Challenges in magnetic recording

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Overview Hard Drive
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Overview Hard Drive
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Science in Magnetic Storage

• Physics
• Chemistry
• Materials Science
• Mechanical Engineering
• Electrical Engineering
• Signal Processing

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Historical Progress
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Hysteresis in Magnetic Media
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Hysteresis in Single Domains
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Longitudinal Recording
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Recording Head Fabrication
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Inductive Head Fabrication
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Read Element Fabrication
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Giant Magneto-Resistance
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Giant Magneto-Resistance
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Spin-Valve Sensor
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Thin Film Media Disk Structure
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Thin Film Magnetic Media
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Flying in Hard Drive
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Magnetic Storage Challenges

• Thermal Decay
• Dynamic Limits
• Field Sensitivity
• Lithography

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Thermal Decay
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Antiferromagnetically Coupled Magnetic Media
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Perpendicular Recording
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Patterned Magnetic Media
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Recording in Patterned Media
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Multi-Level Magnetic Storage
M. Albrecht et al. J. Appl. Phys. 97, 103910
(2005)
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Dynamic Effects
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Magnetic Field Sensitivity
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Lithography Limits