Scientists at The University of Manchester have designed a molecule that can remember magnetic information at the highest temperature ever recorded for this kind of material.
In a boon for the future of data storage technologies, the researchers have made a new single-molecule magnet that retains its magnetic memory up to 100 Kelvin (-173 °C) - around the temperature of the Moon at night.
The finding, published in the journal Nature, is a significant advance on the previous record of 80 Kelvin (-193 °C). While still a long way from working in a standard freezer, or at room temperature, data storage at 100 Kelvin could be feasible in huge data centres, such as those used by Google.
If perfected, these single-molecule magnets could pack vast amounts of information into incredibly small spaces - possibly more than three terabytes of data per square centimetre. That's around half a million TikTok videos squeezed into a hard drive that's the size of a postage stamp.
The research was led by The University of Manchester, with computational modelling led by the Australian National University (ANU).
David Mills, Professor of Inorganic Chemistry at The University of Manchester, said: "This research showcases the power of chemists to deliberately design and build molecules with targeted properties. The results are an exciting prospect for the use of single-molecule magnets in data storage media that is 100 times more dense than the absolute limit of current technologies.
"Although the new magnet still needs cooling far below room temperature, it is now well above the temperature of liquid nitrogen (77 Kelvin), which is a readily available coolant. So, while we won't be seeing this type of data storage in our mobile phones for a while, it does make storing information in huge data centres more feasible."
Magnetic materials have long played an important role in data storage technologies. Currently, hard drives store data by magnetising tiny regions made up of many atoms all working together to retain memory. Single-molecule magnets can store information individually and don't need help from any neighbouring atoms to retain their memory, offering the potential for incredibly high data density. But, until now, the challenge has always been the incredibly cold temperatures needed in order for them to function.
The key to the new magnets' success is its unique structure, with the element dysprosium located between two nitrogen atoms. These three atoms are arranged almost in a straight line - a configuration predicted to boost magnetic performance but realised now for the first time.
Usually, when dysprosium is bonded to only two nitrogen atoms it tends to form molecules with more bent or irregular shapes. In the new molecule, the researchers added a chemical group called an alkene that acts like a molecular pin, binding to dysprosium to hold the structure in place.
The team at the Australian National University developed a new theoretical model to simulate the molecule's magnetic behaviour to allow them to explain why this particular molecular magnet performs so well compared to previous designs.
Now, the researchers will use these results as a blueprint to guide the design of even better molecular magnets.
