Magnetism: and then there were four
Discovery opens the door to a new computer device design. Andrew Masterson reports.
Ruthenium, the element that sits at number 44 on the periodic table, has been discovered to be magnetic at room temperature – becoming only the fourth element shown to be so.
The discovery, made by a team of scientists led by Patrick Quarterman of the US National Institute of Standards and Technology (NIST) paves the way for a new generation of sensors, computer devices and spintronic applications.
The first element known to be magnetic at room temperature, iron, was discovered many thousands of years ago. Two more – cobalt and nickel – were added more recently. Another, the rare earth gadolinium, is also magnetic, but only when its temperature is raised some eight degrees Celsius above room temperature.
Quarterman and his colleagues reveal ruthenium’s properties in a paper in the journal Nature Communications.
To make the discovery the team had to first find a way to “grow” the element into a structure that forced it into a magnetic phase. The correct form turned out to be an ultra-thin film – making it potentially very useful for next-gen electronics applications, many of which require manipulation on an atomic scale.
“This is an exciting but hard problem,” says co-author Jian-Ping Wang from the University of Minnesota in the US.
“It took us about two years to find a right way to grow this material and validate it. This work will trigger the magnetic research community to look into fundamental aspects of magnetism for many well-known elements.”