Groundbreaking study paves way for faster, more energy-efficient hard disks
In a pioneering study, physicists have successfully manipulated the magnetic properties of rare earth elements using laser pulses. This achievement marks the first instance of such an alteration, challenging long-standing assumptions that these properties were unchangeable. These findings could pave the way for the creation of faster, superior, and more energy-efficient data storage devices in the future. The researchers utilized two powerful X-ray lasers, EuXFEL (European X-ray Free-Electron Laser) and FLASH (Free-Electron Laser in Hamburg), both stationed in Hamburg, Germany.
X-ray lasers enable observation of elemental processes
The EuXFEL and FLASH lasers are capable of generating ultrashort X-ray pulses. The study authors explained, "These X-ray sources allow us to observe elementary processes in magnetic materials on time scales of a few femtoseconds." A femtosecond (10^-15 s) is one-millionth of a billionth of a second. This capability has opened new avenues for observing and influencing the behavior of rare-earth elements at an unprecedented level.
Terbium's magnetic properties altered
The researchers focused on the 4f electrons of terbium, a rare-earth metal with eight electrons in its 4f orbitals. They exposed samples of terbium to X-ray laser pulses from FLASH and EuXFEL, and analyzed the metal's electronic structure via X-ray spectroscopy. This exposure led to a redistribution of 4f electrons, temporarily altering terbium's magnetic properties. The study authors reported an "ultrafast change of 4f orbital states."
Potential impact on data storage technology
The newfound ability to control the magnetic properties of rare-earth metals could revolutionize data storage technology. Specifically, it could enhance heat-assisted magnetic recording (HAMR) storage devices, like hard disk drives, currently using metal alloys containing iron, platinum, cobalt, and others. The researchers noted that "with the much stronger rare-earth magnets, an ultrashort laser pulse could now excite the 4f electrons and enable switching—an electronic effect that would be even faster and more efficient than the heating mechanism in HAMR memory."
