Mumbai: Agroup of Indian and Swedish researchers has identified new materials that could power next generation of digital devices.
Quantum mechanics is at the heart ofcutting edge technologies like data storage on the ‘cloud’, portable terabyte hard drives, andhigh speedRAMs. All such applications come under the umbrella of spintronics or spin electronics. Scientists from Indian Institute of Technology (IIT) Guwahati and Uppsala University, Sweden have identified new magnetic materials for use in spintronics.
Electrons carry charge through electronic devices. In addition, they also possess a property known as ‘spin’, which can have either of two orientations: ‘spin-up’ or ‘spin-down’ in the presence of small magnetic fields. Spin electronics makes use of an electron’s spin in addition to its charge to create a plethora of possibilities that can be harnessed to increase transfer speeds and storage capacities in electronic devices.
A set of materials known as Intermetallic Heusler compounds have specific magnetic properties suited for spintronics applications. Indian and Swedish researchers carried out a systematic search for morecompounds of this family that could potentially be used in spintronics devices. They focused on two series of compoundsfrom the Heuseler family containing elements that possess some magnetic properties: Co-X’-Mn-Si and Co-X’-Fe-Si, where X’ is the mystery element. By substituting each of the nine elements from Yttrium to Silver in the periodic table in the place of X’, they obtained a list of 18 compounds as potential candidates.
"They focused on two series of compoundsfrom the Heuseler family containing elements that possess some magnetic properties: Co-X’-Mn-Si and Co-X’-Fe-Si, where X’ is the mystery element."
Researchers further applied a computational modelling method - Density Functional Theory (DFT) - to investigate electronic, structural and magnetic properties of materials. This analysis resulted in identification of two compounds, Co-Tc-Mn-Si and Co-Rh-Mn-Si, containing technetium and rhodium respectively. In addition to good electronic structure and stability, these two compounds were found to possess the properties of half metallicity and a high Curie temperature, which are much sought-after inspintronics applications.
Half metallicity implies that a material conducts only for one spin orientation and acts as an insulator for the other, allowing for customised and safe conduction in devices. Devices also get heated up with prolonged usage or exposure to high temperatures, having a negative impact on the magnetic properties of the materials used in them. This can be averted by using materials with high Curie temperatures.
Through their findings, the researchers were also able to establish that half metallic compounds do not necessarily have high Curie temperatures. This is an interesting consequence that can help tailor future research efforts for new materials. The study results have been published in journal Scientific Reports.
The research team included AshisKundu, Srikrishna Ghosh, Rudra Banerjee, Subhradip Ghosh and Biplab Sanyal. (India Science Wire)