View Full Version : Why Manganese-Gallium Is Not The Next Neodymium-Iron-Boron

13th January 2012, 07:19 PM
Why Manganese-Gallium Is Not The Next Neodymium-Iron-Boron

I’ve received a number of emails today from people wanting to hear my thoughts on a news release from Northeastern University published earlier today, pertaining to a new magnetic material that researchers at the University have apparently discovered.

According to the announcement, the “super-strong magnetic material” may “revolutionize the production of magnets found in computers, mobile phones, electric cars and wind-powered generators“. According to one of the co-authors of the study, “[s]tate-of-the-art electric motors and generators contain highly coercive magnets that are based on rare-earth elements, but we have developed a new material with similar properties without those exotic elements“.

The material is apparently based on a compound of manganese (Mn) and gallium (Ga), with Northeastern claiming that the material “can be synthesized on the nanoscale to produce a coercive field that rivals materials containing rare-earth elements, which are considerably more expensive to process and mine“.

The message boards are abuzz with this announcement, apparently with many people (i.e. retail investors in the rare-earth sector) now worried that this material is the death knell for permanent magnets based on the rare earths neodymium / praseodymium (Nd / Pr), and thus the hopes and dreams for untold riches from these commodities…

Take a deep breath, folks. Being a materials scientist by training, I am naturally a big fan of ongoing research & development work on new engineering materials, and I will read with interest more details on this research, in a forthcoming edition of Applied Physics Letters. I am much less of a fan of the now well-worn path of hype disguised as scientific (and more importantly engineering) breakthroughs, which this announcement represents. Here’s why:

While Mn is cheap as chips, Ga is at present 2-3 times more expensive than Nd / Pr;
The production of Ga is approximately 200 tpa – of which perhaps 100 tpa comes from recycling – and it is presently all spoken for. Compare this to the more than 20-25 ktpa of Nd + Pr available each year, and the prospects for multiples of this production rate in the near future, from new sources of supply.
All new Ga is produced as a byproduct of aluminum and zinc production. The supply dynamics of these two metals alone will determine future availability of Ga – not its potential use in a permanent-magnet material.
Given the painfully long road to commercialization for other materials that rely on similar processing routes, it is highly unlikely that synthesis “at the nanoscale” will be less expensive than mining and processing rare earths any time soon.
Finally, while we’re at it – a “highly coercive” magnet material, is not the same thing as a “super-strong” magnetic material. The former refers to the ability of a material to resist being demagnetized; the latter to the ability of the magnet to do work.
This new Mn-Ga compound is certainly very interesting scientifically; but unless someone finds a primary Ga deposit, and can perfect inexpensive nanoscale material production, it’s not going to “revolutionize the production of magnets found in computers, mobile phones, electric cars and wind-powered generators” anytime soon.