Molecule-sized magnets could promise leap for data storage capacity

Storage capacity could increase a thousandfold

Scientists in the UK have created a magnet no larger than a molecule which could vastly expand hard drive storage capacity and allow huge volumes of data to be stored in tiny places.

 

Most computer users know the frustration of running out of data storage space. No matter how big your hard drive, massive files like high-definition films and large photo collections often end up cluttering it.

Researchers around the world have long been looking for new technology to dramatically increase computer memory space, making it something of a Holy Grail in the industry.

Now, scientists at the University of Nottingham have come up with a new molecule which could lead to a breakthrough in the search for boosting computer data storage capacity.

Today's hard drives are already incredibly small - they could shrink further

Steve Liddle, an expert in molecular depleted uranium chemistry at the university, points to a glass tube containing a bit of dark blue material.

It's a tiny fraction of a new molecule which he has created. Each is a magnet - a so-called single molecule magnet. You can't make a smaller magnet than that, he adds.

"The difference with a single molecule magnet is that the magnetization you can get from these molecules derives exclusively from molecular origin - so it's actually the molecule itself which is generating the magnetism," said Liddle.

Cramming more into less

Liddle, who published a paper on the subject last month, believes that a magnet that small could be hugely significant to boosting computer storage space.

That's because modern computer hard disk drives work magnetically. The data is stored digitally as tiny magnetized regions, called bits, on the disk.

The bits are written and read by separate elements in a recording head as it flies over the spinning disk.

"The aim of a manufacturer of a hard disk is to try to get more and more information onto the disk so that you can store more information in a smaller space," said Martyn Poliakoff, a chemistry professor at the University of Nottingham.

Today's hard disk magnets are already incredibly small, just a few hundred nanometers wide. Yet that is big compared to single molecule magnets. Using these could increase data storage a thousandfold.

Heat poses a hurdle

But it may be a while before these molecule magnets make their way into computer hard drives. That's due to something called blocking temperature, according to Liddle.

"Blocking temperature is the temperature below which the magnetization that you have is stable - and above this temperature it scrambles and it loses the information that you have," he explained. "That would be like having a computer hard drive which on a hot day would lose all of your data."

To fix that, the molecule's spin state needs to be increased.

The hunt for the Holy Grail of data storage is heating up

That's how many electrons are spinning around the atomic core - the more the better. Liddle's single molecule magnet is made up of two uranium atoms.

"We have a compound with two uranium atoms in it, and what we need to do is build up molecules with many, many uranium atoms in them and that will build up the spin state and hopefully it should build up the blocking temperature," said Liddle.

Hunt for the Holy Grail

But, he admits, once his team is able to get around the blocking temperature, it might take a few more years at least before computer hard drives become a thousand times larger than the terabyte drives currently available.

"The next step is then to get them into systems which could actually be used in a hard drive and to then find out whether they are actually any good from a technological standpoint," said Liddle.

But computer storage technology develops fast, and magnets could be made redundant by solutions like flash drive technology, which you already find in smartphones and more and more laptop computers.

For now, magnetic hard drives are cheaper and bigger but they're approaching the limit of how small usable magnets can be, and therefore how much data can be stored in a certain space.

It means the hunt for the Holy Grail of data storage is heating up, and with that - hopefully - speeding up too.

Author: Lars Bevanger / sp
Editor: Martin Kuebler

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