Scientists exploring the magnetic phenomena in the microscopic scale have made two separate breakthroughs in molecular and atomic magnetism that could revolutionize data storage.
However, the magnetic phenomenon extends to the microscopic world, down to single atoms.
Scientists are just beginning to scratch the surface of atomic and molecular magnetism and unravel some of its secrets.
High-Temperature Single-Molecule Magnets
Discovered in the 1990s, Single-molecule magnets (SMMs) are metalorganic macromolecules that, only below a certain point called blocking temperature, exhibit supramagnetism.
SMMs are particularly interesting for data storage technology. SMM-based devices would be able to store high-density data by leveraging the nuclear spin reversal of individual molecules.
But one issue has been limiting SMMs development and adoption — low blocking temperatures.
An international team of chemists from the University of Sussex (UK), Sun-Yat-Sen University (China), and the University of Jyväskylä (Finland) have found a way around that.
The team has designed new high-temperature single-molecule magnets “with a blocking temperature above 77 K, the boiling point of liquid nitrogen, which is both cheap and readily available.”
Since their introduction in 1993, single-molecule magnets were dependent on liquid helium, which is both rare, expensive, and has a very low blocking temperature.
“Single-molecule magnets have been firmly stuck in the liquid-helium temperature regime for over a quarter of a century,” said Professor Richard Layfield who led the research. “Having previously proposed a blueprint for the molecular structure of a high-temperature SMM, we have now refined our design strategy to a level that allows access to the first such material. Our new result is a milestone that overcomes a major obstacle to developing new molecular information storage materials and we are excited about the prospects for advancing the field even further.”
Full details of the research can be found in Science Magazine.
Accessing Atomic Magnetism
While single-molecule magnets belong to the molecular scale, magnetism as a phenomenon goes even deeper, down to the atomic and subatomic levels.
Also collaborated in the research are researchers from IBM Research, the University of Oxford, and the International Iberian Nanotechnology Laboratory.
For the first time, the team was able to detect the nuclear spin of a single atom “which describes the magnetism of the atom’s core”, while usually the detection of the nuclear spin is only possible in very large numbers.
The main instrument that aided the team is an advanced Scanning Tunneling Microscope (STM) at IBM Research which allows the investigation of single atoms with great accuracy.
Besides the first application that comes to mind with nuclear magnetism, and that’s storing data in the nuclear spin of atoms themselves, this breakthrough could have big implications for research in areas yet to be explored.
“I am very excited about these results. It is certainly a milestone in our field and has very promising implications for future research,” said Andreas Heinrich, QNS Director. “By addressing individual nuclear spins we can gain deeper knowledge about the structure of matter and open new fields of basic research.”
The study appeared in the journal Science.