Researchers say that ferrimagnets-based spintronics devices could be faster than ferromagnets ones

Researchers from MIT, the Max-Born Institute, Technische Universität Berlin and the Deutsches Elektronen-Synchrotron (DESY) say ferrimagnets-based spintronics devices could be faster than ferromagnets ones.

Pt/Co44Gd56 ferrimagnetic schematic

Ferromagnets are traditional magnets - such as iron. Ferrimagnets are materials that have two types of ions with magnetic moments that are not equal - and are also polarized in opposite directions.Using these two ion types could be used, according to the researchers, to create smaller bits in magnetic memory as these will allow faster domain wall dynamics to occur.

Researchers from Mainz University demonstrate the basic principles of ultra-fast and stable memory based on Mn2Au antiferromagnets

Researchers from Mainz University demonstrate the basic principles of ultra-fast and stable memory based on the antiferromagnet Mn2Au. Antiferromagnetic materials are challenging to manipulate and to implement a read-out process (of the Neel vector orientation on).

Crystal structure of Mn2Au with antiferromagnetically ordered magnetic moments.

Up until now, researchers were only able to use a single antiferromagnetic material - copper manganese arsenide (CuMnAs), but this material had several disadvantages. The new compound, manganese and gold (Mn2Au) offers for example ten times larger magnetoresistance and other important advantages including its non-toxic composition and the fact that it can be used even at higher temperatures.

Researcher discover a 2D material that possessed an intrinsic ferromagnetism.

Researchers from the DoE's Lawrence Berkeley National Laboratory discovered that 2-D chromium germanium telluride (CGT) feature an intrinsic ferromagnetism. Up until now it was not clear whether magnetism could survive in such thin materials - but this discovery proved that it could of course.

Detecting electron spin in CGT, Berkeley

The CGT flakes were produced using exfoliating (the scotch-tape method, the same one used to produce graphene in Manchester in 2004). This discovery can lead to extremely thin spintronic devices.

Researchers finally explain ferromagnetism in Mn-doped GaAs

Researchers at Tohoku University managed to find the origin and the mechanism of ferromagnetism in Mn-doped GaAs. This phenomonon has been puzzling researchers for over 20 years, and this new explanation may help to accelerate the development of spintronic devices made from such materials.

Tohoku Crystal structure of (Ga,Mn)As

Mn-doped GaAs crystals exhibit characteristics and properties of both semiconductor and magnet. It is possible to use an electric field to control the magnetism in such materials - which makes them very appealing candidates for spintronic devices.

Iron-doped ferromagnetic semiconductors at room temperature

Researchers from Japan and Vietnam report an iron-doped ferromagnetic semiconductors at room temperature. They say this is the same time that a ferromagnetic semiconductor is demonstrated, which is seen as a promising spintronic device material.

The researchers say that current theory predicted that a type of semiconductor known as "wide band gap" would be strongly ferromagnetic, and most research focused on that approach. But the researchers chose a narrow-gap semconductor (both indium arsenide and gallium antimonide were chosen) as the host semiconductor, which enabled them to obtain ferromagnetism and conserve it at room temperature by adjusting doping concentrations.

Berkeley Lab Reports on Electric Field Switching of Ferromagnetism at Room Temp

Researchers from the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) and Cornell University managed to use an electric field to reverse the magnetization direction in a multiferroic spintronic device at room temperature.

Berkeley Lab Electric-Field Switching of Ferromagnetism render

The researchers showed that 180-degree magnetization switching in the multiferroic bismuth ferrite can be achieved at room temperature with an external electric field when the kinetics of the switching involves a two-step process. They say that this demonstration, which runs counter to conventional scientific wisdom, points a new way towards spintronics applications.

Researchers manage to switch robust ferromagnetism close to room temperature by using low electric fields

Researchers from Germany, France and the UK managed to switch on and off robust ferromagnetism close to room temperature by using low electric fields. They hope such work will lead to applications in low-power Spintronics devices.

The researchers used a ferroelectric BaTiO3 substrate and covered it with a thin film of magnetic FeRh. They then demonstrated how the magnetic order of the sample changes dramatically, when a moderate external electric field is applied

The source of ferromagnetism in dilute magnetic semiconductors finally explained

Researchers developed a new technique called HARPES (Hard x-ray Angle-Resolved PhotoEmission Spectroscopy) that can be used to investigate the bulk electronic structure of different materials. In the first application, they checked the bulk electronic structure of the prototypical dilute magnetic semiconductor gallium manganese arsenide, and discovered that the material’s ferromagnetism arises from both of the two different mechanisms that have been proposed to explain it. Understanding the source of ferromagnetism in dilute magnetic semiconductors is an important milestone toward using these materials in Spintronics devices.

HARPES, which is based on the photoelectric effect, enables scientists to study bulk electronic effects with minimum interference from surface reactions or contamination. It also allows them to probe buried layers and interfaces that are ubiquitous in nanoscale devices, and are key to smaller logic elements in electronics, novel memory architectures in spintronics, and more efficient energy conversion in photovoltaic cells.

Spintronics researcher likely to be in contention for Nobel honors

Update: Unfortunately, Hideo Ohno did not get the Nobel, which went to Saul Perlmutter, Brian P. Schmidt, Adam G. Riess

According to Thomson Reuters a Spintronics researcher is a likely likely to be in contention for Nobel honors in Physics. They say that Hideo Ohno, Professor of the Laboratory for Nanoelectronics and Spintronics in Tohuku University is Japan may get the price for his contributions to ferromagnetism in diluted magnetic semiconductors.

Electric ferromagnetism at room temperature shown in cobalt-doped titanium dioxide

Researchers from Japan managed to induce and control magnetization in a ferromagnetic semiconductor (cobalt-doped titanium dioxide) at room temperature. This is another step towards room-temperature Spintronics.

The researchers constructed an electric double-layer transistor structure (see above) which uses a liquid electrolyte as a gate insulator, in which a small applied voltage is sufficient to generate a very high electric field.