Room Temperature - Page 3

Researchers from the University of Utah developed Spintronics devices that can convert heat into electricity. Those thermoelectric devices work at room temperature and don't require a continuous external magnetic field.

Those devices (that can convert even minute heat to electricity) function on a concept known as spin-caloritronics, in which thermal and electrical transport occurs in different parts of the device.

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

Researchers from UC Berkeley, Florida International University (FIU) and the Georgia Institute of Technology demonstrated for the first time the presence of magnetic properties in graphene nanostructures at room temperature. This could lead towards Spintronics applications.

To achieve this they functionalized the graphene with nitrophenyl. The researchers thus confirmed the presence of magnetic order in nanoparticle-functionalized graphene. The graphene was epitaxially grown at Georgia Tech, chemically functionalized at UC Riverside and studied at FIU and UC Berkeley.

Researchers from the University of Nottingham are studying a new antiferromagnetic spintronic material - tetragonal CuMnAs. They say that this new material enables new device structure designs that combine Spintronic and nanoelectronic functionality - at room temperature.

An antiferromagnet is a material in which electron spin on adjacent atoms cancel each other out - and so it was considered unsuitable for Spintronics applications. However it was recently discovered that these materials have a physical phenomena that can enable memory and sensing applications.

A combination of Manganese and Gallium Nitride was once a promising spintronics material, but it was later abandoned when it was found that these two materials aren't harmonious. But now researchers from Ohio university (in collaboration with Argentinian and Spanish researchers) developed a way to incorporate a uniform layer (at least on the surface) from the materials.

The researchers used the nitrogen polarity of gallium nitride (old experiments used the gallium polarity) to attach to the manganese, and they also heated the sample which prevents the manganese atoms from "floating" on the outer layer of gallium atoms and instead made the connection that created the manganese-nitrogen bond.

Researchers from Tohoku University have shown that electron spins can be preserved for long distances using optimized organic compounds. This is because organic compounds are made mostly from carbon, in which the spin–orbit interaction is quite small. Using fullerene (C60) films the researchers made devices in which electrons traveled up to 110 nm at room temperature while preserving their spin.

The researchers used fullerence because there's no hydrogen in it (common in other organic materials) and this helps reduce the hyper fine interactions between electron and nuclear spins that can induce spin-flipping events. They built an organic spin valve in which two ferromagnetic electrons are placed in contact with an organic layer.

Researchers from Sweden, Germany and the US managed to develop an effective spin amplifier based on a non-magnetic semiconductor - that works at room temperature. The amplification occurs through deliberate defects in the form of extra gallium atoms introduced into an alloy of gallium, indium, nitrogen and arsenic.

Such a device can be used along a path of spin transport to amplify signals that have weakened along the way. By combining this with a spin detector, it may be possible to read even extremely weak spin signals.

Researchers from the University of Utah developed a Spintronics organic thin-film transistor that can be used as a cheap magnetic field sensor that never needs to be calibrated and is capable of detecting intermediate to strong magnetic fields. The film also resists heat and degradation and operates at room temperatures.

The thin film is an organic semiconductor polymer called MEH-PPV - a very cheap material. In fact the researchers say that this new sensor is "dirt cheap" - it costs just as little as a drop of regular paint. The researchers are thinking about launching a spin-off company to commercialize this technology.

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.

A new study managed to see the showed that barium titanate (BaTiO3) exhibits a multiferroic property (dual traits of both ferroelectric and ferromagnetic) at room temperature using soft X-ray resonant magnetic scattering. The EU-funded project was led by researchers from Germany, France and the United Kingdom.

This unique property of BaTiO3 could be used to make spintronic devices - quickly and cost effectively. The EU's ELISA (European light sources activities - synchrotrons and free electron lasers) project granted 10 million euro to the project, and the FEMMES (FerroElectric Multifunctional tunnel junctions for MEmristors and Spintronics) project contributed a further 2 million euro.