Graphene In 3 Layers Can Make A Rare Magnet
Super material graphene's properties are multifarious. It has strong chemical stability, high conductivity, and super strength.
However, magnetic properties have been a sore point with many skeptics lowering expectations on graphene as a replacement for silicon in future microprocessors.
In a new study, researchers at the Tata Institute of Fundamental Research in India evolved a new type of magnet that optimizes the magnetism of electrons in three-layered graphene at a temperature as low as -272 Celsius.
The study, published in Nature Communications, explains how coordinated whispers between electrons are achieving that ferromagnetism.
Unlike metals, the density of electrons in graphene is too low as it is just one atom thick. That is why illustrating the wave nature of electrons under quantum mechanics with graphene is easy.
That property will be better understood when graphene is contrasted with a metal like copper whose electrons might be scattered every 100 nanometers because of impurities. In sharp contrast, electrons of graphene can travel greater distances up to 10 micrometers.
In the TIFR experiments, this long-range travel of graphene electrons was achieved by sandwiching graphene with boron nitride layers, which are defect free and which refrain from blocking the electron flow.
The ability of a material's electrons to travel great distances implies that there are no flaws and the electrons can conduct soft whispers just like "talking to each other." Reduced flaws are similar to the condition in a silent room where even a soft whisper becomes audible as there are few disturbances.
This whisper of electrons and the resulting magnetism has been explained by doctoral student Biswajit Datta, working with the group of Professor Mandar Deshmukh at TIFR.
The team understood that the silence is enabling enhanced electronic interactions in the three layers of graphene and leading to the formation of a new type of magnet with graphene. The insights explain how electronic devices can leverage graphene for scientific studies and applications.
Already some researchers have offered solutions for making graphene magnetic by inserting hydrogen atoms into specific areas in the graphene lattice.
Physicists from Spain and Egypt have suggested that when a group of electrons in nanoscale domains is encoded with the magnetic spin, they will transform graphene into a spintronic material capable of replacing silicon.
If the experiment succeeds, thanks to hydrogen's single electron property it will be the densest spintronic material ever detected.
A magnetic graphene will have an astounding range of applications starting from information processing to advanced medicine. Magnetic graphene will be playing a big role in spintronics. In the spin transport electronics applications, signals will be processed by magnetic spins in place of electric charges.
The technology offers faster processors and high memory. Miniaturization of silicon transistors is already hitting a plateau. New generation processors including those from Intel are down to 14nm with the 5nm size expected in 2020, marking the possible functional end of small sizes. Magnetic graphene in spintronics may go mainstream and take the place of traditional silicon transistors and work on the atomic scale.
High-Quality Graphene Production
Meanwhile, South Australia's Flinders University and First Graphite Ltd company are aiming high-quality graphene production using Vortex Fluidic Device. Globally, graphite mining runs into millions of metric tons every year.
According to Craig McGuckin, managing director of First Graphite, graphene will be indispensable in a vast number of industries and the demand will be high.
"What is required is creating high-quality graphene from graphite, doing so quickly and efficiently and that is what we are trying to take up now," he said.