Chemists from The University of Manchester and The Australian National University (ANU) have engineered a new type of molecule that can store information at temperatures as cold as the dark side of the moon at night, with major implications for the future of data storage technologies.
The findings, published in Nature, could pave the way for next-generation hardware about the size of a postage stamp that can store 100 times more digital data than current technologies.
"The new single-molecule magnet developed by the research team can retain its magnetic memory up to 100 Kelvin, which is about minus 173 degrees Celsius, or as cold as an evening on the moon," co-lead author Professor Nicholas Chilton, from the ANU Research School of Chemistry, said.
"This is a significant advancement from the previous record of 80 Kelvin, which is around minus 193 degrees Celsius. If perfected, these molecules could pack large amounts of information into tiny spaces.
"Pink Floyd's The Dark Side of the Moon was released in 1973. Technology has come a long way since then and nowadays we listen to music through new digital mediums such as Spotify and even TikTok.
"This new molecule could lead to new technologies that could store about three terabytes of data per square centimetre. That's equivalent to around 40,000 CD copies of The Dark Side of the Moon album squeezed into a hard drive the size of a postage stamp, or around half a million TikTok videos."
With more of us than ever before browsing the web, scrolling social media, streaming videos and uploading files to cloud-based systems, there is a growing demand for new types of information technology infrastructure that can store and process the immense amounts of data that is consumed daily.
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 their neighbours to retain their memory, offering the potential for ultra-high data densities.
But the challenge has always been the incredibly cold temperatures required for them to function.
"While still a long way from working in a standard freezer, or at room temperature, data storage at 100 Kelvin, or about minus 173 degrees Celsius, could be feasible in huge data centres, such as those used by Google," co-lead author Professor David Mills, from The University of Manchester, said.
"Although the new magnet still needs cooling far below room temperature, it is now well above the temperature of liquid nitrogen, a readily available coolant, which is 77 Kelvin, or around minus 196 degrees Celsius.
"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."
The key to the new magnets' success is its unique structure, with the rare earth 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.
"At ANU, we've developed a new theoretical approach to simulate the molecule's magnetic behaviour, using only the fundamental equations of quantum mechanics, which has allowed us to explain why this particular molecular magnet performs so well compared to previous designs," Professor Chilton said.
"We were able to achieve this by leveraging the massive computational resources of the National Computational Infrastructure at ANU and the Pawsey Supercomputing Research Centre in Western Australia, including their large banks of GPU-accelerated compute nodes, to simulate the time-dependence of the electron spins in this molecular material.
"This has enabled us to explain why this new molecule, with its linear arrangement of atoms at its core, can show magnetic memory at such high temperatures. This molecule will now serve as a blueprint moving forward to guide the design of even better molecular magnets that can retain their data at even higher temperatures.
"In the more than 50 years since the release of The Dark Side of the Moon, technology has progressed leaps and bounds. It's exciting to think how technologies will continue to evolve in the next half a century."
This research was jointly led by The University of Manchester and ANU.
