Uploaded May 2017 | Updated September 2026, 2 hours ago
Since the beginning of the digital age, the storage and processing of data has been vital to the use of computers and other digital devices. Hard drives are used for the long-term storage of data in computers. This project will delve into how a hard drive works and future plans with storing information.
The three main components of the hard drive are the spinning platter, the actuator arm, and the read/write head. The functioning of the hard drive is largely dependent on the magnetic properties of the platter. This platter is normally composed of a base layer of aluminum or glass, which are both non-magnetic materials. A layer of chromium is then added to the base to help stabilize the magnetization of the magnetic layer. Next, a layer of a cobalt alloy is added as the magnetic layer.
Information can be stored in the magnetic layer due to cobalt’s unique properties. Since cobalt is a ferromagnet, it can hold a magnetic field, even in the absence of a magnet. Cobalt’s hexagonal crystal structure also improves its ability to maintain magnetic charge over its domain, while also having the property that the charge can be flipped by the read/write head. To write information on the hard drive, the platter spins at high speeds and the write head needle magnetizes small sectors of the disk along a certain track. This magnetization changes the orientation of the magnetic field. In order to read the information, the disk spins, and the needle moves to the track where the information is recorded. The needle then reads the specific magnetization pattern to extract information. Patterns of different magnetic orientations are interpreted as 1s and 0s by the computer. A “1” would represent “on”, while a “0” would represent “off”. Lastly, the whole platter is covered in a very thin carbon overcoat to project the disk from scratches which could destroy the magnetic layer.
One key limitation of this technology is that each piece of information requires a certain amount of space on the hard drive platter, so storage capacity is finite. Perpendicular magnetic recording has increased the data density of hard drives further by storing data vertically into the disk rather than horizontally along the disk. Further attempts are being made to decrease the amount of space required for one byte of information to be stored by decreasing the size of the magnetic grains.
Link to references:
docs.google.com/a/virginia.edu/document/d/1h7GVYInvjR54Lni2QW2oo7pZmsYwoW_M_0fzHdS9HC0/edit?usp=sharingn
Since the beginning of the digital age, the storage and processing of data has been vital to the use of computers and other digital devices. Hard drives are used for the long-term storage of data in computers. This project will delve into how a hard drive works and future plans with storing information.
The three main components of the hard drive are the spinning platter, the actuator arm, and the read/write head. The functioning of the hard drive is largely dependent on the magnetic properties of the platter. This platter is normally composed of a base layer of aluminum or glass, which are both non-magnetic materials. A layer of chromium is then added to the base to help stabilize the magnetization of the magnetic layer. Next, a layer of a cobalt alloy is added as the magnetic layer.
Information can be stored in the magnetic layer due to cobalt’s unique properties. Since cobalt is a ferromagnet, it can hold a magnetic field, even in the absence of a magnet. Cobalt’s hexagonal crystal structure also improves its ability to maintain magnetic charge over its domain, while also having the property that the charge can be flipped by the read/write head. To write information on the hard drive, the platter spins at high speeds and the write head needle magnetizes small sectors of the disk along a certain track. This magnetization changes the orientation of the magnetic field. In order to read the information, the disk spins, and the needle moves to the track where the information is recorded. The needle then reads the specific magnetization pattern to extract information. Patterns of different magnetic orientations are interpreted as 1s and 0s by the computer. A “1” would represent “on”, while a “0” would represent “off”. Lastly, the whole platter is covered in a very thin carbon overcoat to project the disk from scratches which could destroy the magnetic layer.
One key limitation of this technology is that each piece of information requires a certain amount of space on the hard drive platter, so storage capacity is finite. Perpendicular magnetic recording has increased the data density of hard drives further by storing data vertically into the disk rather than horizontally along the disk. Further attempts are being made to decrease the amount of space required for one byte of information to be stored by decreasing the size of the magnetic grains.
Link to references:
docs.google.com/a/virginia.edu/document/d/1h7GVYInvjR54Lni2QW2oo7pZmsYwoW_M_0fzHdS9HC0/edit?usp=sharingn
