Future IT: Antiferromagnetic dysprosium reveals magnetic switching with less energy

November 06, 2017

Dysprosium is not only the atomic element with the strongest magnetic moments, but it also possesses another interesting property: its magnetic moments point either all the same direction (ferromagnetism) or are tilted against each other, depending on the temperature. This makes it possible to investigate in the very same sample how differently oriented magnetic moments behave when they are excited by an external energy pulse.

Magnetic-order perturbation examined at BESSY II

Physicist Dr. Nele Thielemann-Kuehn and her colleagues have now investigated this problem at BESSY II. The BESSY II X-ray source is one of the few facilities worldwide that enables processes as fast as magnetic-order perturbations to be observed. Her finding: the magnetic orientation in antiferromagnetic dysprosium can be much more easily toggled using a short laser pulse than in ferromagnetic dysprosium.

"This is because the magnetic moments at the atomic level are coupled to angular momenta like that of a gyroscope", explains Thielemann-Kuehn. Tipping a rotating gyroscope requires force because its angular momentum must be transferred to another body. "Albert Einstein and Wander Johannes de Haas showed in a famous experiment back in 1915 that when the magnetisation of a suspended bar of iron changes, the bar begins to rotate because the angular momenta of the atomic-level magnets in the suspended bar are transferred to it as a whole. If the atomic-level magnetic momenta are already pointing in different directions initially, their angular momenta can interact with one another and cancel each other out, just as if you were to combine two gyroscopes rotating in opposite direction", clarifies Dr. Christian Schuessler-Langeheine, head of the group.

Antiferromagnetic order is perturbed faster

The transfer of angular momentum takes time, though. Antiferromagnetic order, for which this transfer is not required, should therefore be able to be perturbed faster than ferromagnetic order. The empirical evidence for this conjecture has now been delivered in this study by Thielemann-Kuehn and her colleagues. Moreover, the team also discovered that the energy needed in the case of the antiferromagnetic momenta is considerably lower than in the case of ferromagnetic order.

From this observation, the scientists have been able to suggest how materials could be developed with a combination of ferromagnetic and antiferromagnetic aligned spins that are suitable as magnetic storage media and might be switched with considerably lower energy expenditure than material made from conventional magnets.

Helmholtz-Zentrum Berlin für Materialien und Energie

Related Ferromagnetic Articles from Brightsurf:

A new ultrafast control scheme of ferromagnet for energy-efficient data storage
Using a single laser pulse that did not switch the ferrimagnetic layer, researchers demonstrated a much faster and less energy consuming switching of the ferromagnet.

Twisting magnetization with light
A team of scientists led by the Max Born Institute (MBI), Berlin, Germany, and the Massachusetts Institute of Technology (MIT), Cambridge, USA, has demonstrated how tiny magnetization patterns known as skyrmions can be written into a ferromagnetic material faster than previously thought possible.

Energy-saving servers: Data storage 2.0
A research team of Mainz University has developed a technique that will potentially halve the energy required to write data to servers and make it easier to construct complex server architectures.

Van der Waals junction spin valves without spacer layer
Distinct from traditional spin valves with a sandwich structure consisting of two ferromagnetic metals decoupled by the insertion of a non-magnetic spacer, recently, a research team led by Prof.

Nanoneedles to increase the capacity and robustness of digital memories
Researchers have developed a new technique to locally modify the properties of a metamagnetic material.

NYU and IBM research takes electrons for a spin in moving toward more efficient, higher density data
Researchers at New York University and IBM Research have demonstrated a new mechanism involving electron motion in magnetic materials that points to new ways to potentially enhance data storage.

Toward a more energy-efficient spintronics
In order to generate and detect spin currents, spintronics traditionally uses ferromagnetic materials whose magnetization switching consume high amounts of energy.

Not everything is ferromagnetic in high magnetic fields
High magnetic fields have a potential to modify the microscopic arrangement of magnetic moments because they overcome interactions existing in zero field.

What decides the ferromagnetism in the non-encapsulated few-layer CrI3
A recent study demonstrated the layer, polarization and temperature dependence of the Raman features of non-encapsulated 2-5 layer and bulk CrI3, illustrating that the non-encapsulated few-layer and bulk CrI3 are rhombohedral stacking order at low temperature, rather than monoclinic structure.

Paving the way for spintronic RAMs: A deeper look into a powerful spin phenomenon
Scientists at Tokyo Institute of Technology explore a new material combination that sets the stage for magnetic random access memories, which rely on spin -- an intrinsic property of electrons -- and could outperform current storage devices.

Read More: Ferromagnetic News and Ferromagnetic Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.