According to the team, the Mn2RuxGa magnetic alloy – or MRG – has some unusual properties that may allow it to revolutionise data storage, as well as increase wireless data transmission speeds significantly.
The material has no net magnetic moment, but full spin polarisation. No magnetic moment is said to free the material from its own demagnetising forces, as well as being immune to the influence of any external magnetic fields. This property, coupled with full spin polarisation, means the material should be extremely efficient when used in spintronics applications.
A further benefit is its potential to shift the ferromagnetic resonance frequency – the maximum speed at which data is written or retrieved – into the low terahertz range.
The secret was in combining manganese with ruthenium, said researcher Dr Karsten Rode. "Manganese is in the 'Goldilocks zone' – the magnetic coupling of the electrons is neither too strong nor too weak – just right."
"The most difficult part was to understand that our new material was truly special," Dr Rode continued. "Once we realised there was a possibility that we could achieve full compensation of the magnetic moments, coupled with a large spin polarisation, we started checking to see if the 'zero moment half metal' hypothesis would stand intense scrutiny – and it did."
The team now wants to demonstrate spintronic functionality in a practical device. "This is challenging for a manganese based alloy," Dr Rode concluded. "The manganese is easily oxidised and this has to be avoided in a fully-functional thin-film device stack. But now that we think we understand the conditions necessary to create a zero-moment half metal, it is likely that MRG will not long remain an 'only child'."
